1	// SPDX-License-Identifier: GPL-2.0
2	/*
3	* Copyright (C) 2007 Oracle. All rights reserved.
4	*/
5
6	#include <linux/sched.h>
7	#include <linux/sched/mm.h>
8	#include <linux/slab.h>
9	#include <linux/spinlock.h>
10	#include <linux/completion.h>
11	#include <linux/bug.h>
12	#include <linux/list.h>
13	#include <linux/string_choices.h>
14	#include <crypto/hash.h>
15	#include "messages.h"
16	#include "ctree.h"
17	#include "discard.h"
18	#include "disk-io.h"
19	#include "send.h"
20	#include "transaction.h"
21	#include "sysfs.h"
22	#include "volumes.h"
23	#include "space-info.h"
24	#include "block-group.h"
25	#include "qgroup.h"
26	#include "misc.h"
27	#include "fs.h"
28	#include "accessors.h"
29
30	/*
31	* Structure name Path
32	* --------------------------------------------------------------------------
33	* btrfs_supported_static_feature_attrs /sys/fs/btrfs/features
34	* btrfs_supported_feature_attrs /sys/fs/btrfs/features and
35	* /sys/fs/btrfs/<uuid>/features
36	* btrfs_attrs /sys/fs/btrfs/<uuid>
37	* devid_attrs /sys/fs/btrfs/<uuid>/devinfo/<devid>
38	* allocation_attrs /sys/fs/btrfs/<uuid>/allocation
39	* qgroup_attrs /sys/fs/btrfs/<uuid>/qgroups/<level>_<qgroupid>
40	* space_info_attrs /sys/fs/btrfs/<uuid>/allocation/<bg-type>
41	* raid_attrs /sys/fs/btrfs/<uuid>/allocation/<bg-type>/<bg-profile>
42	* discard_attrs /sys/fs/btrfs/<uuid>/discard
43	*
44	* When built with BTRFS_CONFIG_DEBUG:
45	*
46	* btrfs_debug_feature_attrs /sys/fs/btrfs/debug
47	* btrfs_debug_mount_attrs /sys/fs/btrfs/<uuid>/debug
48	*/
49
50	struct btrfs_feature_attr {
51	struct kobj_attribute kobj_attr;
52	enum btrfs_feature_set feature_set;
53	u64 feature_bit;
54	};
55
56	/* For raid type sysfs entries */
57	struct raid_kobject {
58	u64 flags;
59	struct kobject kobj;
60	};
61
62	#define __INIT_KOBJ_ATTR(_name, _mode, _show, _store) \
63	{ \
64	.attr = { .name = __stringify(_name), .mode = _mode }, \
65	.show = _show, \
66	.store = _store, \
67	}
68
69	#define BTRFS_ATTR_W(_prefix, _name, _store) \
70	static struct kobj_attribute btrfs_attr_##_prefix##_##_name = \
71	__INIT_KOBJ_ATTR(_name, 0200, NULL, _store)
72
73	#define BTRFS_ATTR_RW(_prefix, _name, _show, _store) \
74	static struct kobj_attribute btrfs_attr_##_prefix##_##_name = \
75	__INIT_KOBJ_ATTR(_name, 0644, _show, _store)
76
77	#define BTRFS_ATTR(_prefix, _name, _show) \
78	static struct kobj_attribute btrfs_attr_##_prefix##_##_name = \
79	__INIT_KOBJ_ATTR(_name, 0444, _show, NULL)
80
81	#define BTRFS_ATTR_PTR(_prefix, _name) \
82	(&btrfs_attr_##_prefix##_##_name.attr)
83
84	#define BTRFS_FEAT_ATTR(_name, _feature_set, _feature_prefix, _feature_bit) \
85	static struct btrfs_feature_attr btrfs_attr_features_##_name = { \
86	.kobj_attr = __INIT_KOBJ_ATTR(_name, S_IRUGO, \
87	btrfs_feature_attr_show, \
88	btrfs_feature_attr_store), \
89	.feature_set = _feature_set, \
90	.feature_bit = _feature_prefix ##_## _feature_bit, \
91	}
92	#define BTRFS_FEAT_ATTR_PTR(_name) \
93	(&btrfs_attr_features_##_name.kobj_attr.attr)
94
95	#define BTRFS_FEAT_ATTR_COMPAT(name, feature) \
96	BTRFS_FEAT_ATTR(name, FEAT_COMPAT, BTRFS_FEATURE_COMPAT, feature)
97	#define BTRFS_FEAT_ATTR_COMPAT_RO(name, feature) \
98	BTRFS_FEAT_ATTR(name, FEAT_COMPAT_RO, BTRFS_FEATURE_COMPAT_RO, feature)
99	#define BTRFS_FEAT_ATTR_INCOMPAT(name, feature) \
100	BTRFS_FEAT_ATTR(name, FEAT_INCOMPAT, BTRFS_FEATURE_INCOMPAT, feature)
101
102	static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj);
103	static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj);
104	static struct kobject *get_btrfs_kobj(struct kobject *kobj);
105
106	static struct btrfs_feature_attr *to_btrfs_feature_attr(struct kobj_attribute *a)
107	{
108	return container_of(a, struct btrfs_feature_attr, kobj_attr);
109	}
110
111	static struct kobj_attribute *attr_to_btrfs_attr(struct attribute *attr)
112	{
113	return container_of(attr, struct kobj_attribute, attr);
114	}
115
116	static struct btrfs_feature_attr *attr_to_btrfs_feature_attr(
117	struct attribute *attr)
118	{
119	return to_btrfs_feature_attr(a: attr_to_btrfs_attr(attr));
120	}
121
122	static u64 get_features(struct btrfs_fs_info *fs_info,
123	enum btrfs_feature_set set)
124	{
125	struct btrfs_super_block *disk_super = fs_info->super_copy;
126	if (set == FEAT_COMPAT)
127	return btrfs_super_compat_flags(s: disk_super);
128	else if (set == FEAT_COMPAT_RO)
129	return btrfs_super_compat_ro_flags(s: disk_super);
130	else
131	return btrfs_super_incompat_flags(s: disk_super);
132	}
133
134	static void set_features(struct btrfs_fs_info *fs_info,
135	enum btrfs_feature_set set, u64 features)
136	{
137	struct btrfs_super_block *disk_super = fs_info->super_copy;
138	if (set == FEAT_COMPAT)
139	btrfs_set_super_compat_flags(s: disk_super, val: features);
140	else if (set == FEAT_COMPAT_RO)
141	btrfs_set_super_compat_ro_flags(s: disk_super, val: features);
142	else
143	btrfs_set_super_incompat_flags(s: disk_super, val: features);
144	}
145
146	static int can_modify_feature(struct btrfs_feature_attr *fa)
147	{
148	int val = 0;
149	u64 set, clear;
150	switch (fa->feature_set) {
151	case FEAT_COMPAT:
152	set = BTRFS_FEATURE_COMPAT_SAFE_SET;
153	clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
154	break;
155	case FEAT_COMPAT_RO:
156	set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
157	clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
158	break;
159	case FEAT_INCOMPAT:
160	set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
161	clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
162	break;
163	default:
164	btrfs_warn(NULL, "sysfs: unknown feature set %d", fa->feature_set);
165	return 0;
166	}
167
168	if (set & fa->feature_bit)
169	val |= 1;
170	if (clear & fa->feature_bit)
171	val |= 2;
172
173	return val;
174	}
175
176	static ssize_t btrfs_feature_attr_show(struct kobject *kobj,
177	struct kobj_attribute *a, char *buf)
178	{
179	int val = 0;
180	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
181	struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
182	if (fs_info) {
183	u64 features = get_features(fs_info, set: fa->feature_set);
184	if (features & fa->feature_bit)
185	val = 1;
186	} else
187	val = can_modify_feature(fa);
188
189	return sysfs_emit(buf, fmt: "%d\n", val);
190	}
191
192	static ssize_t btrfs_feature_attr_store(struct kobject *kobj,
193	struct kobj_attribute *a,
194	const char *buf, size_t count)
195	{
196	struct btrfs_fs_info *fs_info;
197	struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
198	u64 features, set, clear;
199	unsigned long val;
200	int ret;
201
202	fs_info = to_fs_info(kobj);
203	if (!fs_info)
204	return -EPERM;
205
206	if (sb_rdonly(sb: fs_info->sb))
207	return -EROFS;
208
209	ret = kstrtoul(s: skip_spaces(buf), base: 0, res: &val);
210	if (ret)
211	return ret;
212
213	if (fa->feature_set == FEAT_COMPAT) {
214	set = BTRFS_FEATURE_COMPAT_SAFE_SET;
215	clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
216	} else if (fa->feature_set == FEAT_COMPAT_RO) {
217	set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
218	clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
219	} else {
220	set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
221	clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
222	}
223
224	features = get_features(fs_info, set: fa->feature_set);
225
226	/* Nothing to do */
227	if ((val && (features & fa->feature_bit)) ||
228	(!val && !(features & fa->feature_bit)))
229	return count;
230
231	if ((val && !(set & fa->feature_bit)) ||
232	(!val && !(clear & fa->feature_bit))) {
233	btrfs_info(fs_info,
234	"%sabling feature %s on mounted fs is not supported.",
235	val ? "En" : "Dis", fa->kobj_attr.attr.name);
236	return -EPERM;
237	}
238
239	btrfs_info(fs_info, "%s %s feature flag",
240	val ? "Setting" : "Clearing", fa->kobj_attr.attr.name);
241
242	spin_lock(lock: &fs_info->super_lock);
243	features = get_features(fs_info, set: fa->feature_set);
244	if (val)
245	features |= fa->feature_bit;
246	else
247	features &= ~fa->feature_bit;
248	set_features(fs_info, set: fa->feature_set, features);
249	spin_unlock(lock: &fs_info->super_lock);
250
251	/*
252	* We don't want to do full transaction commit from inside sysfs
253	*/
254	set_bit(nr: BTRFS_FS_NEED_TRANS_COMMIT, addr: &fs_info->flags);
255	wake_up_process(tsk: fs_info->transaction_kthread);
256
257	return count;
258	}
259
260	static umode_t btrfs_feature_visible(struct kobject *kobj,
261	struct attribute *attr, int unused)
262	{
263	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
264	umode_t mode = attr->mode;
265
266	if (fs_info) {
267	struct btrfs_feature_attr *fa;
268	u64 features;
269
270	fa = attr_to_btrfs_feature_attr(attr);
271	features = get_features(fs_info, set: fa->feature_set);
272
273	if (can_modify_feature(fa))
274	mode |= S_IWUSR;
275	else if (!(features & fa->feature_bit))
276	mode = 0;
277	}
278
279	return mode;
280	}
281
282	BTRFS_FEAT_ATTR_INCOMPAT(default_subvol, DEFAULT_SUBVOL);
283	BTRFS_FEAT_ATTR_INCOMPAT(mixed_groups, MIXED_GROUPS);
284	BTRFS_FEAT_ATTR_INCOMPAT(compress_lzo, COMPRESS_LZO);
285	BTRFS_FEAT_ATTR_INCOMPAT(compress_zstd, COMPRESS_ZSTD);
286	BTRFS_FEAT_ATTR_INCOMPAT(extended_iref, EXTENDED_IREF);
287	BTRFS_FEAT_ATTR_INCOMPAT(raid56, RAID56);
288	BTRFS_FEAT_ATTR_INCOMPAT(skinny_metadata, SKINNY_METADATA);
289	BTRFS_FEAT_ATTR_INCOMPAT(no_holes, NO_HOLES);
290	BTRFS_FEAT_ATTR_INCOMPAT(metadata_uuid, METADATA_UUID);
291	BTRFS_FEAT_ATTR_COMPAT_RO(free_space_tree, FREE_SPACE_TREE);
292	BTRFS_FEAT_ATTR_COMPAT_RO(block_group_tree, BLOCK_GROUP_TREE);
293	BTRFS_FEAT_ATTR_INCOMPAT(raid1c34, RAID1C34);
294	BTRFS_FEAT_ATTR_INCOMPAT(simple_quota, SIMPLE_QUOTA);
295	#ifdef CONFIG_BLK_DEV_ZONED
296	BTRFS_FEAT_ATTR_INCOMPAT(zoned, ZONED);
297	#endif
298	#ifdef CONFIG_BTRFS_EXPERIMENTAL
299	/* Remove once support for extent tree v2 is feature complete */
300	BTRFS_FEAT_ATTR_INCOMPAT(extent_tree_v2, EXTENT_TREE_V2);
301	/* Remove once support for raid stripe tree is feature complete. */
302	BTRFS_FEAT_ATTR_INCOMPAT(raid_stripe_tree, RAID_STRIPE_TREE);
303	#endif
304	#ifdef CONFIG_FS_VERITY
305	BTRFS_FEAT_ATTR_COMPAT_RO(verity, VERITY);
306	#endif
307
308	/*
309	* Features which depend on feature bits and may differ between each fs.
310	*
311	* /sys/fs/btrfs/features - all available features implemented by this version
312	* /sys/fs/btrfs/UUID/features - features of the fs which are enabled or
313	* can be changed on a mounted filesystem.
314	*/
315	static struct attribute *btrfs_supported_feature_attrs[] = {
316	BTRFS_FEAT_ATTR_PTR(default_subvol),
317	BTRFS_FEAT_ATTR_PTR(mixed_groups),
318	BTRFS_FEAT_ATTR_PTR(compress_lzo),
319	BTRFS_FEAT_ATTR_PTR(compress_zstd),
320	BTRFS_FEAT_ATTR_PTR(extended_iref),
321	BTRFS_FEAT_ATTR_PTR(raid56),
322	BTRFS_FEAT_ATTR_PTR(skinny_metadata),
323	BTRFS_FEAT_ATTR_PTR(no_holes),
324	BTRFS_FEAT_ATTR_PTR(metadata_uuid),
325	BTRFS_FEAT_ATTR_PTR(free_space_tree),
326	BTRFS_FEAT_ATTR_PTR(raid1c34),
327	BTRFS_FEAT_ATTR_PTR(block_group_tree),
328	BTRFS_FEAT_ATTR_PTR(simple_quota),
329	#ifdef CONFIG_BLK_DEV_ZONED
330	BTRFS_FEAT_ATTR_PTR(zoned),
331	#endif
332	#ifdef CONFIG_BTRFS_EXPERIMENTAL
333	BTRFS_FEAT_ATTR_PTR(extent_tree_v2),
334	BTRFS_FEAT_ATTR_PTR(raid_stripe_tree),
335	#endif
336	#ifdef CONFIG_FS_VERITY
337	BTRFS_FEAT_ATTR_PTR(verity),
338	#endif
339	NULL
340	};
341
342	static const struct attribute_group btrfs_feature_attr_group = {
343	.name = "features",
344	.is_visible = btrfs_feature_visible,
345	.attrs = btrfs_supported_feature_attrs,
346	};
347
348	static ssize_t rmdir_subvol_show(struct kobject *kobj,
349	struct kobj_attribute *ka, char *buf)
350	{
351	return sysfs_emit(buf, fmt: "0\n");
352	}
353	BTRFS_ATTR(static_feature, rmdir_subvol, rmdir_subvol_show);
354
355	static ssize_t supported_checksums_show(struct kobject *kobj,
356	struct kobj_attribute *a, char *buf)
357	{
358	ssize_t ret = 0;
359	int i;
360
361	for (i = 0; i < btrfs_get_num_csums(); i++) {
362	/*
363	* This "trick" only works as long as 'enum btrfs_csum_type' has
364	* no holes in it
365	*/
366	ret += sysfs_emit_at(buf, at: ret, fmt: "%s%s", (i == 0 ? "" : " "),
367	btrfs_super_csum_name(csum_type: i));
368
369	}
370
371	ret += sysfs_emit_at(buf, at: ret, fmt: "\n");
372	return ret;
373	}
374	BTRFS_ATTR(static_feature, supported_checksums, supported_checksums_show);
375
376	static ssize_t send_stream_version_show(struct kobject *kobj,
377	struct kobj_attribute *ka, char *buf)
378	{
379	return sysfs_emit(buf, fmt: "%d\n", BTRFS_SEND_STREAM_VERSION);
380	}
381	BTRFS_ATTR(static_feature, send_stream_version, send_stream_version_show);
382
383	static const char *rescue_opts[] = {
384	"usebackuproot",
385	"nologreplay",
386	"ignorebadroots",
387	"ignoredatacsums",
388	"ignoremetacsums",
389	"ignoresuperflags",
390	"all",
391	};
392
393	static ssize_t supported_rescue_options_show(struct kobject *kobj,
394	struct kobj_attribute *a,
395	char *buf)
396	{
397	ssize_t ret = 0;
398	int i;
399
400	for (i = 0; i < ARRAY_SIZE(rescue_opts); i++)
401	ret += sysfs_emit_at(buf, at: ret, fmt: "%s%s", (i ? " " : ""), rescue_opts[i]);
402	ret += sysfs_emit_at(buf, at: ret, fmt: "\n");
403	return ret;
404	}
405	BTRFS_ATTR(static_feature, supported_rescue_options,
406	supported_rescue_options_show);
407
408	static ssize_t supported_sectorsizes_show(struct kobject *kobj,
409	struct kobj_attribute *a,
410	char *buf)
411	{
412	ssize_t ret = 0;
413	bool has_output = false;
414
415	for (u32 cur = BTRFS_MIN_BLOCKSIZE; cur <= BTRFS_MAX_BLOCKSIZE; cur *= 2) {
416	if (!btrfs_supported_blocksize(blocksize: cur))
417	continue;
418	if (has_output)
419	ret += sysfs_emit_at(buf, at: ret, fmt: " ");
420	ret += sysfs_emit_at(buf, at: ret, fmt: "%u", cur);
421	has_output = true;
422	}
423	ret += sysfs_emit_at(buf, at: ret, fmt: "\n");
424	return ret;
425	}
426	BTRFS_ATTR(static_feature, supported_sectorsizes,
427	supported_sectorsizes_show);
428
429	static ssize_t acl_show(struct kobject *kobj, struct kobj_attribute *a, char *buf)
430	{
431	return sysfs_emit(buf, fmt: "%d\n", IS_ENABLED(CONFIG_BTRFS_FS_POSIX_ACL));
432	}
433	BTRFS_ATTR(static_feature, acl, acl_show);
434
435	static ssize_t temp_fsid_supported_show(struct kobject *kobj,
436	struct kobj_attribute *a, char *buf)
437	{
438	return sysfs_emit(buf, fmt: "0\n");
439	}
440	BTRFS_ATTR(static_feature, temp_fsid, temp_fsid_supported_show);
441
442	/*
443	* Features which only depend on kernel version.
444	*
445	* These are listed in /sys/fs/btrfs/features along with
446	* btrfs_supported_feature_attrs.
447	*/
448	static struct attribute *btrfs_supported_static_feature_attrs[] = {
449	BTRFS_ATTR_PTR(static_feature, acl),
450	BTRFS_ATTR_PTR(static_feature, rmdir_subvol),
451	BTRFS_ATTR_PTR(static_feature, supported_checksums),
452	BTRFS_ATTR_PTR(static_feature, send_stream_version),
453	BTRFS_ATTR_PTR(static_feature, supported_rescue_options),
454	BTRFS_ATTR_PTR(static_feature, supported_sectorsizes),
455	BTRFS_ATTR_PTR(static_feature, temp_fsid),
456	NULL
457	};
458
459	static const struct attribute_group btrfs_static_feature_attr_group = {
460	.name = "features",
461	.attrs = btrfs_supported_static_feature_attrs,
462	};
463
464	/*
465	* Discard statistics and tunables
466	*/
467	#define discard_to_fs_info(_kobj) to_fs_info(get_btrfs_kobj(_kobj))
468
469	static ssize_t btrfs_discardable_bytes_show(struct kobject *kobj,
470	struct kobj_attribute *a,
471	char *buf)
472	{
473	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
474
475	return sysfs_emit(buf, fmt: "%lld\n",
476	atomic64_read(v: &fs_info->discard_ctl.discardable_bytes));
477	}
478	BTRFS_ATTR(discard, discardable_bytes, btrfs_discardable_bytes_show);
479
480	static ssize_t btrfs_discardable_extents_show(struct kobject *kobj,
481	struct kobj_attribute *a,
482	char *buf)
483	{
484	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
485
486	return sysfs_emit(buf, fmt: "%d\n",
487	atomic_read(v: &fs_info->discard_ctl.discardable_extents));
488	}
489	BTRFS_ATTR(discard, discardable_extents, btrfs_discardable_extents_show);
490
491	static ssize_t btrfs_discard_bitmap_bytes_show(struct kobject *kobj,
492	struct kobj_attribute *a,
493	char *buf)
494	{
495	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
496
497	return sysfs_emit(buf, fmt: "%llu\n",
498	fs_info->discard_ctl.discard_bitmap_bytes);
499	}
500	BTRFS_ATTR(discard, discard_bitmap_bytes, btrfs_discard_bitmap_bytes_show);
501
502	static ssize_t btrfs_discard_bytes_saved_show(struct kobject *kobj,
503	struct kobj_attribute *a,
504	char *buf)
505	{
506	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
507
508	return sysfs_emit(buf, fmt: "%lld\n",
509	atomic64_read(v: &fs_info->discard_ctl.discard_bytes_saved));
510	}
511	BTRFS_ATTR(discard, discard_bytes_saved, btrfs_discard_bytes_saved_show);
512
513	static ssize_t btrfs_discard_extent_bytes_show(struct kobject *kobj,
514	struct kobj_attribute *a,
515	char *buf)
516	{
517	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
518
519	return sysfs_emit(buf, fmt: "%llu\n",
520	fs_info->discard_ctl.discard_extent_bytes);
521	}
522	BTRFS_ATTR(discard, discard_extent_bytes, btrfs_discard_extent_bytes_show);
523
524	static ssize_t btrfs_discard_iops_limit_show(struct kobject *kobj,
525	struct kobj_attribute *a,
526	char *buf)
527	{
528	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
529
530	return sysfs_emit(buf, fmt: "%u\n",
531	READ_ONCE(fs_info->discard_ctl.iops_limit));
532	}
533
534	static ssize_t btrfs_discard_iops_limit_store(struct kobject *kobj,
535	struct kobj_attribute *a,
536	const char *buf, size_t len)
537	{
538	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
539	struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
540	u32 iops_limit;
541	int ret;
542
543	ret = kstrtou32(s: buf, base: 10, res: &iops_limit);
544	if (ret)
545	return -EINVAL;
546
547	WRITE_ONCE(discard_ctl->iops_limit, iops_limit);
548	btrfs_discard_calc_delay(discard_ctl);
549	btrfs_discard_schedule_work(discard_ctl, override: true);
550	return len;
551	}
552	BTRFS_ATTR_RW(discard, iops_limit, btrfs_discard_iops_limit_show,
553	btrfs_discard_iops_limit_store);
554
555	static ssize_t btrfs_discard_kbps_limit_show(struct kobject *kobj,
556	struct kobj_attribute *a,
557	char *buf)
558	{
559	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
560
561	return sysfs_emit(buf, fmt: "%u\n",
562	READ_ONCE(fs_info->discard_ctl.kbps_limit));
563	}
564
565	static ssize_t btrfs_discard_kbps_limit_store(struct kobject *kobj,
566	struct kobj_attribute *a,
567	const char *buf, size_t len)
568	{
569	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
570	struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
571	u32 kbps_limit;
572	int ret;
573
574	ret = kstrtou32(s: buf, base: 10, res: &kbps_limit);
575	if (ret)
576	return -EINVAL;
577
578	WRITE_ONCE(discard_ctl->kbps_limit, kbps_limit);
579	btrfs_discard_schedule_work(discard_ctl, override: true);
580	return len;
581	}
582	BTRFS_ATTR_RW(discard, kbps_limit, btrfs_discard_kbps_limit_show,
583	btrfs_discard_kbps_limit_store);
584
585	static ssize_t btrfs_discard_max_discard_size_show(struct kobject *kobj,
586	struct kobj_attribute *a,
587	char *buf)
588	{
589	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
590
591	return sysfs_emit(buf, fmt: "%llu\n",
592	READ_ONCE(fs_info->discard_ctl.max_discard_size));
593	}
594
595	static ssize_t btrfs_discard_max_discard_size_store(struct kobject *kobj,
596	struct kobj_attribute *a,
597	const char *buf, size_t len)
598	{
599	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
600	struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
601	u64 max_discard_size;
602	int ret;
603
604	ret = kstrtou64(s: buf, base: 10, res: &max_discard_size);
605	if (ret)
606	return -EINVAL;
607
608	WRITE_ONCE(discard_ctl->max_discard_size, max_discard_size);
609
610	return len;
611	}
612	BTRFS_ATTR_RW(discard, max_discard_size, btrfs_discard_max_discard_size_show,
613	btrfs_discard_max_discard_size_store);
614
615	/*
616	* Per-filesystem stats for discard (when mounted with discard=async).
617	*
618	* Path: /sys/fs/btrfs/<uuid>/discard/
619	*/
620	static const struct attribute *discard_attrs[] = {
621	BTRFS_ATTR_PTR(discard, discardable_bytes),
622	BTRFS_ATTR_PTR(discard, discardable_extents),
623	BTRFS_ATTR_PTR(discard, discard_bitmap_bytes),
624	BTRFS_ATTR_PTR(discard, discard_bytes_saved),
625	BTRFS_ATTR_PTR(discard, discard_extent_bytes),
626	BTRFS_ATTR_PTR(discard, iops_limit),
627	BTRFS_ATTR_PTR(discard, kbps_limit),
628	BTRFS_ATTR_PTR(discard, max_discard_size),
629	NULL,
630	};
631
632	#ifdef CONFIG_BTRFS_DEBUG
633
634	/*
635	* Per-filesystem runtime debugging exported via sysfs.
636	*
637	* Path: /sys/fs/btrfs/UUID/debug/
638	*/
639	static const struct attribute *btrfs_debug_mount_attrs[] = {
640	NULL,
641	};
642
643	/*
644	* Runtime debugging exported via sysfs, applies to all mounted filesystems.
645	*
646	* Path: /sys/fs/btrfs/debug
647	*/
648	static struct attribute *btrfs_debug_feature_attrs[] = {
649	NULL
650	};
651
652	static const struct attribute_group btrfs_debug_feature_attr_group = {
653	.name = "debug",
654	.attrs = btrfs_debug_feature_attrs,
655	};
656
657	#endif
658
659	static ssize_t btrfs_show_u64(u64 *value_ptr, spinlock_t *lock, char *buf)
660	{
661	u64 val;
662	if (lock)
663	spin_lock(lock);
664	val = *value_ptr;
665	if (lock)
666	spin_unlock(lock);
667	return sysfs_emit(buf, fmt: "%llu\n", val);
668	}
669
670	static ssize_t global_rsv_size_show(struct kobject *kobj,
671	struct kobj_attribute *ka, char *buf)
672	{
673	struct btrfs_fs_info *fs_info = to_fs_info(kobj: kobj->parent);
674	struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
675	return btrfs_show_u64(value_ptr: &block_rsv->size, lock: &block_rsv->lock, buf);
676	}
677	BTRFS_ATTR(allocation, global_rsv_size, global_rsv_size_show);
678
679	static ssize_t global_rsv_reserved_show(struct kobject *kobj,
680	struct kobj_attribute *a, char *buf)
681	{
682	struct btrfs_fs_info *fs_info = to_fs_info(kobj: kobj->parent);
683	struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
684	return btrfs_show_u64(value_ptr: &block_rsv->reserved, lock: &block_rsv->lock, buf);
685	}
686	BTRFS_ATTR(allocation, global_rsv_reserved, global_rsv_reserved_show);
687
688	#define to_space_info(_kobj) container_of(_kobj, struct btrfs_space_info, kobj)
689	#define to_raid_kobj(_kobj) container_of(_kobj, struct raid_kobject, kobj)
690
691	static ssize_t raid_bytes_show(struct kobject *kobj,
692	struct kobj_attribute *attr, char *buf);
693	BTRFS_ATTR(raid, total_bytes, raid_bytes_show);
694	BTRFS_ATTR(raid, used_bytes, raid_bytes_show);
695
696	static ssize_t raid_bytes_show(struct kobject *kobj,
697	struct kobj_attribute *attr, char *buf)
698
699	{
700	struct btrfs_space_info *sinfo = to_space_info(kobj->parent);
701	struct btrfs_block_group *block_group;
702	int index = btrfs_bg_flags_to_raid_index(to_raid_kobj(kobj)->flags);
703	u64 val = 0;
704
705	down_read(sem: &sinfo->groups_sem);
706	list_for_each_entry(block_group, &sinfo->block_groups[index], list) {
707	if (&attr->attr == BTRFS_ATTR_PTR(raid, total_bytes))
708	val += block_group->length;
709	else
710	val += block_group->used;
711	}
712	up_read(sem: &sinfo->groups_sem);
713	return sysfs_emit(buf, fmt: "%llu\n", val);
714	}
715
716	/*
717	* Allocation information about block group profiles.
718	*
719	* Path: /sys/fs/btrfs/<uuid>/allocation/<bg-type>/<bg-profile>/
720	*/
721	static struct attribute *raid_attrs[] = {
722	BTRFS_ATTR_PTR(raid, total_bytes),
723	BTRFS_ATTR_PTR(raid, used_bytes),
724	NULL
725	};
726	ATTRIBUTE_GROUPS(raid);
727
728	static void release_raid_kobj(struct kobject *kobj)
729	{
730	kfree(to_raid_kobj(kobj));
731	}
732
733	static const struct kobj_type btrfs_raid_ktype = {
734	.sysfs_ops = &kobj_sysfs_ops,
735	.release = release_raid_kobj,
736	.default_groups = raid_groups,
737	};
738
739	#define SPACE_INFO_ATTR(field) \
740	static ssize_t btrfs_space_info_show_##field(struct kobject *kobj, \
741	struct kobj_attribute *a, \
742	char *buf) \
743	{ \
744	struct btrfs_space_info *sinfo = to_space_info(kobj); \
745	return btrfs_show_u64(&sinfo->field, &sinfo->lock, buf); \
746	} \
747	BTRFS_ATTR(space_info, field, btrfs_space_info_show_##field)
748
749	static ssize_t btrfs_chunk_size_show(struct kobject *kobj,
750	struct kobj_attribute *a, char *buf)
751	{
752	struct btrfs_space_info *sinfo = to_space_info(kobj);
753
754	return sysfs_emit(buf, fmt: "%llu\n", READ_ONCE(sinfo->chunk_size));
755	}
756
757	/*
758	* Store new chunk size in space info. Can be called on a read-only filesystem.
759	*
760	* If the new chunk size value is larger than 10% of free space it is reduced
761	* to match that limit. Alignment must be to 256M and the system chunk size
762	* cannot be set.
763	*/
764	static ssize_t btrfs_chunk_size_store(struct kobject *kobj,
765	struct kobj_attribute *a,
766	const char *buf, size_t len)
767	{
768	struct btrfs_space_info *space_info = to_space_info(kobj);
769	struct btrfs_fs_info *fs_info = to_fs_info(kobj: get_btrfs_kobj(kobj));
770	char *retptr;
771	u64 val;
772
773	if (!capable(CAP_SYS_ADMIN))
774	return -EPERM;
775
776	if (!fs_info->fs_devices)
777	return -EINVAL;
778
779	if (btrfs_is_zoned(fs_info))
780	return -EINVAL;
781
782	/* System block type must not be changed. */
783	if (space_info->flags & BTRFS_BLOCK_GROUP_SYSTEM)
784	return -EPERM;
785
786	val = memparse(ptr: buf, retptr: &retptr);
787	/* There could be trailing '\n', also catch any typos after the value */
788	retptr = skip_spaces(retptr);
789	if (*retptr != 0 || val == 0)
790	return -EINVAL;
791
792	val = min(val, BTRFS_MAX_DATA_CHUNK_SIZE);
793
794	/* Limit stripe size to 10% of available space. */
795	val = min(mult_perc(fs_info->fs_devices->total_rw_bytes, 10), val);
796
797	/* Must be multiple of 256M. */
798	val &= ~((u64)SZ_256M - 1);
799
800	/* Must be at least 256M. */
801	if (val < SZ_256M)
802	return -EINVAL;
803
804	btrfs_update_space_info_chunk_size(space_info, chunk_size: val);
805
806	return len;
807	}
808
809	static ssize_t btrfs_size_classes_show(struct kobject *kobj,
810	struct kobj_attribute *a, char *buf)
811	{
812	struct btrfs_space_info *sinfo = to_space_info(kobj);
813	struct btrfs_block_group *bg;
814	u32 none = 0;
815	u32 small = 0;
816	u32 medium = 0;
817	u32 large = 0;
818
819	for (int i = 0; i < BTRFS_NR_RAID_TYPES; ++i) {
820	down_read(sem: &sinfo->groups_sem);
821	list_for_each_entry(bg, &sinfo->block_groups[i], list) {
822	if (!btrfs_block_group_should_use_size_class(bg))
823	continue;
824	switch (bg->size_class) {
825	case BTRFS_BG_SZ_NONE:
826	none++;
827	break;
828	case BTRFS_BG_SZ_SMALL:
829	small++;
830	break;
831	case BTRFS_BG_SZ_MEDIUM:
832	medium++;
833	break;
834	case BTRFS_BG_SZ_LARGE:
835	large++;
836	break;
837	}
838	}
839	up_read(sem: &sinfo->groups_sem);
840	}
841	return sysfs_emit(buf, fmt: "none %u\n"
842	"small %u\n"
843	"medium %u\n"
844	"large %u\n",
845	none, small, medium, large);
846	}
847
848	#ifdef CONFIG_BTRFS_DEBUG
849	/*
850	* Request chunk allocation with current chunk size.
851	*/
852	static ssize_t btrfs_force_chunk_alloc_store(struct kobject *kobj,
853	struct kobj_attribute *a,
854	const char *buf, size_t len)
855	{
856	struct btrfs_space_info *space_info = to_space_info(kobj);
857	struct btrfs_fs_info *fs_info = to_fs_info(kobj: get_btrfs_kobj(kobj));
858	struct btrfs_trans_handle *trans;
859	bool val;
860	int ret;
861
862	if (!capable(CAP_SYS_ADMIN))
863	return -EPERM;
864
865	if (sb_rdonly(sb: fs_info->sb))
866	return -EROFS;
867
868	ret = kstrtobool(s: buf, res: &val);
869	if (ret)
870	return ret;
871
872	if (!val)
873	return -EINVAL;
874
875	/*
876	* This is unsafe to be called from sysfs context and may cause
877	* unexpected problems.
878	*/
879	trans = btrfs_start_transaction(root: fs_info->tree_root, num_items: 0);
880	if (IS_ERR(ptr: trans))
881	return PTR_ERR(ptr: trans);
882	ret = btrfs_force_chunk_alloc(trans, type: space_info->flags);
883	btrfs_end_transaction(trans);
884
885	if (ret == 1)
886	return len;
887
888	return -ENOSPC;
889	}
890	BTRFS_ATTR_W(space_info, force_chunk_alloc, btrfs_force_chunk_alloc_store);
891
892	#endif
893
894	SPACE_INFO_ATTR(flags);
895	SPACE_INFO_ATTR(total_bytes);
896	SPACE_INFO_ATTR(bytes_used);
897	SPACE_INFO_ATTR(bytes_pinned);
898	SPACE_INFO_ATTR(bytes_reserved);
899	SPACE_INFO_ATTR(bytes_may_use);
900	SPACE_INFO_ATTR(bytes_readonly);
901	SPACE_INFO_ATTR(bytes_zone_unusable);
902	SPACE_INFO_ATTR(disk_used);
903	SPACE_INFO_ATTR(disk_total);
904	SPACE_INFO_ATTR(reclaim_count);
905	SPACE_INFO_ATTR(reclaim_bytes);
906	SPACE_INFO_ATTR(reclaim_errors);
907	BTRFS_ATTR_RW(space_info, chunk_size, btrfs_chunk_size_show, btrfs_chunk_size_store);
908	BTRFS_ATTR(space_info, size_classes, btrfs_size_classes_show);
909
910	static ssize_t btrfs_sinfo_bg_reclaim_threshold_show(struct kobject *kobj,
911	struct kobj_attribute *a,
912	char *buf)
913	{
914	struct btrfs_space_info *space_info = to_space_info(kobj);
915	ssize_t ret;
916
917	spin_lock(lock: &space_info->lock);
918	ret = sysfs_emit(buf, fmt: "%d\n", btrfs_calc_reclaim_threshold(space_info));
919	spin_unlock(lock: &space_info->lock);
920	return ret;
921	}
922
923	static ssize_t btrfs_sinfo_bg_reclaim_threshold_store(struct kobject *kobj,
924	struct kobj_attribute *a,
925	const char *buf, size_t len)
926	{
927	struct btrfs_space_info *space_info = to_space_info(kobj);
928	int thresh;
929	int ret;
930
931	if (READ_ONCE(space_info->dynamic_reclaim))
932	return -EINVAL;
933
934	ret = kstrtoint(s: buf, base: 10, res: &thresh);
935	if (ret)
936	return ret;
937
938	if (thresh < 0 || thresh > 100)
939	return -EINVAL;
940
941	WRITE_ONCE(space_info->bg_reclaim_threshold, thresh);
942
943	return len;
944	}
945
946	BTRFS_ATTR_RW(space_info, bg_reclaim_threshold,
947	btrfs_sinfo_bg_reclaim_threshold_show,
948	btrfs_sinfo_bg_reclaim_threshold_store);
949
950	static ssize_t btrfs_sinfo_dynamic_reclaim_show(struct kobject *kobj,
951	struct kobj_attribute *a,
952	char *buf)
953	{
954	struct btrfs_space_info *space_info = to_space_info(kobj);
955
956	return sysfs_emit(buf, fmt: "%d\n", READ_ONCE(space_info->dynamic_reclaim));
957	}
958
959	static ssize_t btrfs_sinfo_dynamic_reclaim_store(struct kobject *kobj,
960	struct kobj_attribute *a,
961	const char *buf, size_t len)
962	{
963	struct btrfs_space_info *space_info = to_space_info(kobj);
964	int dynamic_reclaim;
965	int ret;
966
967	ret = kstrtoint(s: buf, base: 10, res: &dynamic_reclaim);
968	if (ret)
969	return ret;
970
971	if (dynamic_reclaim < 0)
972	return -EINVAL;
973
974	WRITE_ONCE(space_info->dynamic_reclaim, dynamic_reclaim != 0);
975
976	return len;
977	}
978
979	BTRFS_ATTR_RW(space_info, dynamic_reclaim,
980	btrfs_sinfo_dynamic_reclaim_show,
981	btrfs_sinfo_dynamic_reclaim_store);
982
983	static ssize_t btrfs_sinfo_periodic_reclaim_show(struct kobject *kobj,
984	struct kobj_attribute *a,
985	char *buf)
986	{
987	struct btrfs_space_info *space_info = to_space_info(kobj);
988
989	return sysfs_emit(buf, fmt: "%d\n", READ_ONCE(space_info->periodic_reclaim));
990	}
991
992	static ssize_t btrfs_sinfo_periodic_reclaim_store(struct kobject *kobj,
993	struct kobj_attribute *a,
994	const char *buf, size_t len)
995	{
996	struct btrfs_space_info *space_info = to_space_info(kobj);
997	int periodic_reclaim;
998	int ret;
999
1000	ret = kstrtoint(s: buf, base: 10, res: &periodic_reclaim);
1001	if (ret)
1002	return ret;
1003
1004	if (periodic_reclaim < 0)
1005	return -EINVAL;
1006
1007	WRITE_ONCE(space_info->periodic_reclaim, periodic_reclaim != 0);
1008
1009	return len;
1010	}
1011
1012	BTRFS_ATTR_RW(space_info, periodic_reclaim,
1013	btrfs_sinfo_periodic_reclaim_show,
1014	btrfs_sinfo_periodic_reclaim_store);
1015
1016	/*
1017	* Allocation information about block group types.
1018	*
1019	* Path: /sys/fs/btrfs/<uuid>/allocation/<bg-type>/
1020	*/
1021	static struct attribute *space_info_attrs[] = {
1022	BTRFS_ATTR_PTR(space_info, flags),
1023	BTRFS_ATTR_PTR(space_info, total_bytes),
1024	BTRFS_ATTR_PTR(space_info, bytes_used),
1025	BTRFS_ATTR_PTR(space_info, bytes_pinned),
1026	BTRFS_ATTR_PTR(space_info, bytes_reserved),
1027	BTRFS_ATTR_PTR(space_info, bytes_may_use),
1028	BTRFS_ATTR_PTR(space_info, bytes_readonly),
1029	BTRFS_ATTR_PTR(space_info, bytes_zone_unusable),
1030	BTRFS_ATTR_PTR(space_info, disk_used),
1031	BTRFS_ATTR_PTR(space_info, disk_total),
1032	BTRFS_ATTR_PTR(space_info, bg_reclaim_threshold),
1033	BTRFS_ATTR_PTR(space_info, dynamic_reclaim),
1034	BTRFS_ATTR_PTR(space_info, chunk_size),
1035	BTRFS_ATTR_PTR(space_info, size_classes),
1036	BTRFS_ATTR_PTR(space_info, reclaim_count),
1037	BTRFS_ATTR_PTR(space_info, reclaim_bytes),
1038	BTRFS_ATTR_PTR(space_info, reclaim_errors),
1039	BTRFS_ATTR_PTR(space_info, periodic_reclaim),
1040	#ifdef CONFIG_BTRFS_DEBUG
1041	BTRFS_ATTR_PTR(space_info, force_chunk_alloc),
1042	#endif
1043	NULL,
1044	};
1045	ATTRIBUTE_GROUPS(space_info);
1046
1047	static void space_info_release(struct kobject *kobj)
1048	{
1049	struct btrfs_space_info *sinfo = to_space_info(kobj);
1050	kfree(objp: sinfo);
1051	}
1052
1053	static const struct kobj_type space_info_ktype = {
1054	.sysfs_ops = &kobj_sysfs_ops,
1055	.release = space_info_release,
1056	.default_groups = space_info_groups,
1057	};
1058
1059	/*
1060	* Allocation information about block groups.
1061	*
1062	* Path: /sys/fs/btrfs/<uuid>/allocation/
1063	*/
1064	static const struct attribute *allocation_attrs[] = {
1065	BTRFS_ATTR_PTR(allocation, global_rsv_reserved),
1066	BTRFS_ATTR_PTR(allocation, global_rsv_size),
1067	NULL,
1068	};
1069
1070	static ssize_t btrfs_label_show(struct kobject *kobj,
1071	struct kobj_attribute *a, char *buf)
1072	{
1073	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1074	char *label = fs_info->super_copy->label;
1075	ssize_t ret;
1076
1077	spin_lock(lock: &fs_info->super_lock);
1078	ret = sysfs_emit(buf, fmt: label[0] ? "%s\n" : "%s", label);
1079	spin_unlock(lock: &fs_info->super_lock);
1080
1081	return ret;
1082	}
1083
1084	static ssize_t btrfs_label_store(struct kobject *kobj,
1085	struct kobj_attribute *a,
1086	const char *buf, size_t len)
1087	{
1088	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1089	size_t p_len;
1090
1091	if (!fs_info)
1092	return -EPERM;
1093
1094	if (sb_rdonly(sb: fs_info->sb))
1095	return -EROFS;
1096
1097	/*
1098	* p_len is the len until the first occurrence of either
1099	* '\n' or '\0'
1100	*/
1101	p_len = strcspn(buf, "\n");
1102
1103	if (p_len >= BTRFS_LABEL_SIZE)
1104	return -EINVAL;
1105
1106	spin_lock(lock: &fs_info->super_lock);
1107	memset(fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE);
1108	memcpy(fs_info->super_copy->label, buf, p_len);
1109	spin_unlock(lock: &fs_info->super_lock);
1110
1111	/*
1112	* We don't want to do full transaction commit from inside sysfs
1113	*/
1114	set_bit(nr: BTRFS_FS_NEED_TRANS_COMMIT, addr: &fs_info->flags);
1115	wake_up_process(tsk: fs_info->transaction_kthread);
1116
1117	return len;
1118	}
1119	BTRFS_ATTR_RW(, label, btrfs_label_show, btrfs_label_store);
1120
1121	static ssize_t btrfs_nodesize_show(struct kobject *kobj,
1122	struct kobj_attribute *a, char *buf)
1123	{
1124	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1125
1126	return sysfs_emit(buf, fmt: "%u\n", fs_info->nodesize);
1127	}
1128
1129	BTRFS_ATTR(, nodesize, btrfs_nodesize_show);
1130
1131	static ssize_t btrfs_sectorsize_show(struct kobject *kobj,
1132	struct kobj_attribute *a, char *buf)
1133	{
1134	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1135
1136	return sysfs_emit(buf, fmt: "%u\n", fs_info->sectorsize);
1137	}
1138
1139	BTRFS_ATTR(, sectorsize, btrfs_sectorsize_show);
1140
1141	static ssize_t btrfs_commit_stats_show(struct kobject *kobj,
1142	struct kobj_attribute *a, char *buf)
1143	{
1144	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1145	u64 now = ktime_get_ns();
1146	u64 start_time = fs_info->commit_stats.critical_section_start_time;
1147	u64 pending = 0;
1148
1149	if (start_time)
1150	pending = now - start_time;
1151
1152	return sysfs_emit(buf,
1153	fmt: "commits %llu\n"
1154	"cur_commit_ms %llu\n"
1155	"last_commit_ms %llu\n"
1156	"max_commit_ms %llu\n"
1157	"total_commit_ms %llu\n",
1158	fs_info->commit_stats.commit_count,
1159	div_u64(dividend: pending, NSEC_PER_MSEC),
1160	div_u64(dividend: fs_info->commit_stats.last_commit_dur, NSEC_PER_MSEC),
1161	div_u64(dividend: fs_info->commit_stats.max_commit_dur, NSEC_PER_MSEC),
1162	div_u64(dividend: fs_info->commit_stats.total_commit_dur, NSEC_PER_MSEC));
1163	}
1164
1165	static ssize_t btrfs_commit_stats_store(struct kobject *kobj,
1166	struct kobj_attribute *a,
1167	const char *buf, size_t len)
1168	{
1169	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1170	unsigned long val;
1171	int ret;
1172
1173	if (!fs_info)
1174	return -EPERM;
1175
1176	if (!capable(CAP_SYS_RESOURCE))
1177	return -EPERM;
1178
1179	ret = kstrtoul(s: buf, base: 10, res: &val);
1180	if (ret)
1181	return ret;
1182	if (val)
1183	return -EINVAL;
1184
1185	WRITE_ONCE(fs_info->commit_stats.max_commit_dur, 0);
1186
1187	return len;
1188	}
1189	BTRFS_ATTR_RW(, commit_stats, btrfs_commit_stats_show, btrfs_commit_stats_store);
1190
1191	static ssize_t btrfs_clone_alignment_show(struct kobject *kobj,
1192	struct kobj_attribute *a, char *buf)
1193	{
1194	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1195
1196	return sysfs_emit(buf, fmt: "%u\n", fs_info->sectorsize);
1197	}
1198
1199	BTRFS_ATTR(, clone_alignment, btrfs_clone_alignment_show);
1200
1201	static ssize_t quota_override_show(struct kobject *kobj,
1202	struct kobj_attribute *a, char *buf)
1203	{
1204	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1205	int quota_override;
1206
1207	quota_override = test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
1208	return sysfs_emit(buf, fmt: "%d\n", quota_override);
1209	}
1210
1211	static ssize_t quota_override_store(struct kobject *kobj,
1212	struct kobj_attribute *a,
1213	const char *buf, size_t len)
1214	{
1215	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1216	unsigned long knob;
1217	int ret;
1218
1219	if (!fs_info)
1220	return -EPERM;
1221
1222	if (!capable(CAP_SYS_RESOURCE))
1223	return -EPERM;
1224
1225	ret = kstrtoul(s: buf, base: 10, res: &knob);
1226	if (ret)
1227	return ret;
1228	if (knob > 1)
1229	return -EINVAL;
1230
1231	if (knob)
1232	set_bit(nr: BTRFS_FS_QUOTA_OVERRIDE, addr: &fs_info->flags);
1233	else
1234	clear_bit(nr: BTRFS_FS_QUOTA_OVERRIDE, addr: &fs_info->flags);
1235
1236	return len;
1237	}
1238
1239	BTRFS_ATTR_RW(, quota_override, quota_override_show, quota_override_store);
1240
1241	static ssize_t btrfs_metadata_uuid_show(struct kobject *kobj,
1242	struct kobj_attribute *a, char *buf)
1243	{
1244	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1245
1246	return sysfs_emit(buf, fmt: "%pU\n", fs_info->fs_devices->metadata_uuid);
1247	}
1248
1249	BTRFS_ATTR(, metadata_uuid, btrfs_metadata_uuid_show);
1250
1251	static ssize_t btrfs_checksum_show(struct kobject *kobj,
1252	struct kobj_attribute *a, char *buf)
1253	{
1254	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1255	u16 csum_type = btrfs_super_csum_type(s: fs_info->super_copy);
1256
1257	return sysfs_emit(buf, fmt: "%s (%s)\n",
1258	btrfs_super_csum_name(csum_type),
1259	crypto_shash_driver_name(tfm: fs_info->csum_shash));
1260	}
1261
1262	BTRFS_ATTR(, checksum, btrfs_checksum_show);
1263
1264	static ssize_t btrfs_exclusive_operation_show(struct kobject *kobj,
1265	struct kobj_attribute *a, char *buf)
1266	{
1267	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1268	const char *str;
1269
1270	switch (READ_ONCE(fs_info->exclusive_operation)) {
1271	case BTRFS_EXCLOP_NONE:
1272	str = "none\n";
1273	break;
1274	case BTRFS_EXCLOP_BALANCE:
1275	str = "balance\n";
1276	break;
1277	case BTRFS_EXCLOP_BALANCE_PAUSED:
1278	str = "balance paused\n";
1279	break;
1280	case BTRFS_EXCLOP_DEV_ADD:
1281	str = "device add\n";
1282	break;
1283	case BTRFS_EXCLOP_DEV_REMOVE:
1284	str = "device remove\n";
1285	break;
1286	case BTRFS_EXCLOP_DEV_REPLACE:
1287	str = "device replace\n";
1288	break;
1289	case BTRFS_EXCLOP_RESIZE:
1290	str = "resize\n";
1291	break;
1292	case BTRFS_EXCLOP_SWAP_ACTIVATE:
1293	str = "swap activate\n";
1294	break;
1295	default:
1296	str = "UNKNOWN\n";
1297	break;
1298	}
1299	return sysfs_emit(buf, fmt: "%s", str);
1300	}
1301	BTRFS_ATTR(, exclusive_operation, btrfs_exclusive_operation_show);
1302
1303	static ssize_t btrfs_generation_show(struct kobject *kobj,
1304	struct kobj_attribute *a, char *buf)
1305	{
1306	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1307
1308	return sysfs_emit(buf, fmt: "%llu\n", btrfs_get_fs_generation(fs_info));
1309	}
1310	BTRFS_ATTR(, generation, btrfs_generation_show);
1311
1312	static ssize_t btrfs_temp_fsid_show(struct kobject *kobj,
1313	struct kobj_attribute *a, char *buf)
1314	{
1315	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1316
1317	return sysfs_emit(buf, fmt: "%d\n", fs_info->fs_devices->temp_fsid);
1318	}
1319	BTRFS_ATTR(, temp_fsid, btrfs_temp_fsid_show);
1320
1321	static const char *btrfs_read_policy_name[] = {
1322	"pid",
1323	#ifdef CONFIG_BTRFS_EXPERIMENTAL
1324	"round-robin",
1325	"devid",
1326	#endif
1327	};
1328
1329	#ifdef CONFIG_BTRFS_EXPERIMENTAL
1330
1331	/* Global module configuration parameters. */
1332	static char *read_policy;
1333	char *btrfs_get_mod_read_policy(void)
1334	{
1335	return read_policy;
1336	}
1337
1338	/* Set perms to 0, disable /sys/module/btrfs/parameter/read_policy interface. */
1339	module_param(read_policy, charp, 0);
1340	MODULE_PARM_DESC(read_policy,
1341	"Global read policy: pid (default), round-robin[:<min_contig_read>], devid[:<devid>]");
1342	#endif
1343
1344	int btrfs_read_policy_to_enum(const char *str, s64 *value_ret)
1345	{
1346	char param[32];
1347	char __maybe_unused *value_str;
1348
1349	if (!str || strlen(str) == 0)
1350	return 0;
1351
1352	strscpy(param, str);
1353
1354	#ifdef CONFIG_BTRFS_EXPERIMENTAL
1355	/* Separate value from input in policy:value format. */
1356	value_str = strchr(param, ':');
1357	if (value_str) {
1358	char *retptr;
1359
1360	*value_str = 0;
1361	value_str++;
1362	if (!value_ret)
1363	return -EINVAL;
1364
1365	*value_ret = memparse(ptr: value_str, retptr: &retptr);
1366	/* There could be any trailing typos after the value. */
1367	retptr = skip_spaces(retptr);
1368	if (*retptr != 0 || *value_ret <= 0)
1369	return -EINVAL;
1370	}
1371	#endif
1372
1373	return sysfs_match_string(btrfs_read_policy_name, param);
1374	}
1375
1376	#ifdef CONFIG_BTRFS_EXPERIMENTAL
1377	int __init btrfs_read_policy_init(void)
1378	{
1379	s64 value;
1380
1381	if (btrfs_read_policy_to_enum(str: read_policy, value_ret: &value) == -EINVAL) {
1382	btrfs_err(NULL, "invalid read policy or value %s", read_policy);
1383	return -EINVAL;
1384	}
1385
1386	return 0;
1387	}
1388	#endif
1389
1390	static ssize_t btrfs_read_policy_show(struct kobject *kobj,
1391	struct kobj_attribute *a, char *buf)
1392	{
1393	struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
1394	const enum btrfs_read_policy policy = READ_ONCE(fs_devices->read_policy);
1395	ssize_t ret = 0;
1396	int i;
1397
1398	for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
1399	if (ret != 0)
1400	ret += sysfs_emit_at(buf, at: ret, fmt: " ");
1401
1402	if (i == policy)
1403	ret += sysfs_emit_at(buf, at: ret, fmt: "[");
1404
1405	ret += sysfs_emit_at(buf, at: ret, fmt: "%s", btrfs_read_policy_name[i]);
1406
1407	#ifdef CONFIG_BTRFS_EXPERIMENTAL
1408	if (i == BTRFS_READ_POLICY_RR)
1409	ret += sysfs_emit_at(buf, at: ret, fmt: ":%u",
1410	READ_ONCE(fs_devices->rr_min_contig_read));
1411
1412	if (i == BTRFS_READ_POLICY_DEVID)
1413	ret += sysfs_emit_at(buf, at: ret, fmt: ":%llu",
1414	READ_ONCE(fs_devices->read_devid));
1415	#endif
1416	if (i == policy)
1417	ret += sysfs_emit_at(buf, at: ret, fmt: "]");
1418	}
1419
1420	ret += sysfs_emit_at(buf, at: ret, fmt: "\n");
1421
1422	return ret;
1423	}
1424
1425	static ssize_t btrfs_read_policy_store(struct kobject *kobj,
1426	struct kobj_attribute *a,
1427	const char *buf, size_t len)
1428	{
1429	struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
1430	int index;
1431	s64 value = -1;
1432
1433	index = btrfs_read_policy_to_enum(str: buf, value_ret: &value);
1434	if (index < 0)
1435	return -EINVAL;
1436
1437	#ifdef CONFIG_BTRFS_EXPERIMENTAL
1438	/* If moving from RR then disable collecting fs stats. */
1439	if (fs_devices->read_policy == BTRFS_READ_POLICY_RR && index != BTRFS_READ_POLICY_RR)
1440	fs_devices->collect_fs_stats = false;
1441
1442	if (index == BTRFS_READ_POLICY_RR) {
1443	if (value != -1) {
1444	const u32 sectorsize = fs_devices->fs_info->sectorsize;
1445
1446	if (!IS_ALIGNED(value, sectorsize)) {
1447	u64 temp_value = round_up(value, sectorsize);
1448
1449	btrfs_debug(fs_devices->fs_info,
1450	"read_policy: min contig read %lld should be multiple of sectorsize %u, rounded to %llu",
1451	value, sectorsize, temp_value);
1452	value = temp_value;
1453	}
1454	} else {
1455	value = BTRFS_DEFAULT_RR_MIN_CONTIG_READ;
1456	}
1457
1458	if (index != READ_ONCE(fs_devices->read_policy) ||
1459	value != READ_ONCE(fs_devices->rr_min_contig_read)) {
1460	WRITE_ONCE(fs_devices->read_policy, index);
1461	WRITE_ONCE(fs_devices->rr_min_contig_read, value);
1462
1463	btrfs_info(fs_devices->fs_info, "read policy set to '%s:%lld'",
1464	btrfs_read_policy_name[index], value);
1465	}
1466
1467	fs_devices->collect_fs_stats = true;
1468
1469	return len;
1470	}
1471
1472	if (index == BTRFS_READ_POLICY_DEVID) {
1473	if (value != -1) {
1474	BTRFS_DEV_LOOKUP_ARGS(args);
1475
1476	/* Validate input devid. */
1477	args.devid = value;
1478	if (btrfs_find_device(fs_devices, args: &args) == NULL)
1479	return -EINVAL;
1480	} else {
1481	/* Set default devid to the devid of the latest device. */
1482	value = fs_devices->latest_dev->devid;
1483	}
1484
1485	if (index != READ_ONCE(fs_devices->read_policy) ||
1486	value != READ_ONCE(fs_devices->read_devid)) {
1487	WRITE_ONCE(fs_devices->read_policy, index);
1488	WRITE_ONCE(fs_devices->read_devid, value);
1489
1490	btrfs_info(fs_devices->fs_info, "read policy set to '%s:%llu'",
1491	btrfs_read_policy_name[index], value);
1492	}
1493
1494	return len;
1495	}
1496	#endif
1497	if (index != READ_ONCE(fs_devices->read_policy)) {
1498	WRITE_ONCE(fs_devices->read_policy, index);
1499	btrfs_info(fs_devices->fs_info, "read policy set to '%s'",
1500	btrfs_read_policy_name[index]);
1501	}
1502
1503	return len;
1504	}
1505	BTRFS_ATTR_RW(, read_policy, btrfs_read_policy_show, btrfs_read_policy_store);
1506
1507	static ssize_t btrfs_bg_reclaim_threshold_show(struct kobject *kobj,
1508	struct kobj_attribute *a,
1509	char *buf)
1510	{
1511	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1512
1513	return sysfs_emit(buf, fmt: "%d\n", READ_ONCE(fs_info->bg_reclaim_threshold));
1514	}
1515
1516	static ssize_t btrfs_bg_reclaim_threshold_store(struct kobject *kobj,
1517	struct kobj_attribute *a,
1518	const char *buf, size_t len)
1519	{
1520	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1521	int thresh;
1522	int ret;
1523
1524	ret = kstrtoint(s: buf, base: 10, res: &thresh);
1525	if (ret)
1526	return ret;
1527
1528	#ifdef CONFIG_BTRFS_DEBUG
1529	if (thresh != 0 && (thresh > 100))
1530	return -EINVAL;
1531	#else
1532	if (thresh != 0 && (thresh <= 50 || thresh > 100))
1533	return -EINVAL;
1534	#endif
1535
1536	WRITE_ONCE(fs_info->bg_reclaim_threshold, thresh);
1537
1538	return len;
1539	}
1540	BTRFS_ATTR_RW(, bg_reclaim_threshold, btrfs_bg_reclaim_threshold_show,
1541	btrfs_bg_reclaim_threshold_store);
1542
1543	#ifdef CONFIG_BTRFS_EXPERIMENTAL
1544	static ssize_t btrfs_offload_csum_show(struct kobject *kobj,
1545	struct kobj_attribute *a, char *buf)
1546	{
1547	struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
1548
1549	switch (READ_ONCE(fs_devices->offload_csum_mode)) {
1550	case BTRFS_OFFLOAD_CSUM_AUTO:
1551	return sysfs_emit(buf, fmt: "auto\n");
1552	case BTRFS_OFFLOAD_CSUM_FORCE_ON:
1553	return sysfs_emit(buf, fmt: "1\n");
1554	case BTRFS_OFFLOAD_CSUM_FORCE_OFF:
1555	return sysfs_emit(buf, fmt: "0\n");
1556	default:
1557	WARN_ON(1);
1558	return -EINVAL;
1559	}
1560	}
1561
1562	static ssize_t btrfs_offload_csum_store(struct kobject *kobj,
1563	struct kobj_attribute *a, const char *buf,
1564	size_t len)
1565	{
1566	struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
1567	int ret;
1568	bool val;
1569
1570	ret = kstrtobool(s: buf, res: &val);
1571	if (ret == 0)
1572	WRITE_ONCE(fs_devices->offload_csum_mode,
1573	val ? BTRFS_OFFLOAD_CSUM_FORCE_ON : BTRFS_OFFLOAD_CSUM_FORCE_OFF);
1574	else if (ret == -EINVAL && sysfs_streq(s1: buf, s2: "auto"))
1575	WRITE_ONCE(fs_devices->offload_csum_mode, BTRFS_OFFLOAD_CSUM_AUTO);
1576	else
1577	return -EINVAL;
1578
1579	return len;
1580	}
1581	BTRFS_ATTR_RW(, offload_csum, btrfs_offload_csum_show, btrfs_offload_csum_store);
1582	#endif
1583
1584	/*
1585	* Per-filesystem information and stats.
1586	*
1587	* Path: /sys/fs/btrfs/<uuid>/
1588	*/
1589	static const struct attribute *btrfs_attrs[] = {
1590	BTRFS_ATTR_PTR(, label),
1591	BTRFS_ATTR_PTR(, nodesize),
1592	BTRFS_ATTR_PTR(, sectorsize),
1593	BTRFS_ATTR_PTR(, clone_alignment),
1594	BTRFS_ATTR_PTR(, quota_override),
1595	BTRFS_ATTR_PTR(, metadata_uuid),
1596	BTRFS_ATTR_PTR(, checksum),
1597	BTRFS_ATTR_PTR(, exclusive_operation),
1598	BTRFS_ATTR_PTR(, generation),
1599	BTRFS_ATTR_PTR(, read_policy),
1600	BTRFS_ATTR_PTR(, bg_reclaim_threshold),
1601	BTRFS_ATTR_PTR(, commit_stats),
1602	BTRFS_ATTR_PTR(, temp_fsid),
1603	#ifdef CONFIG_BTRFS_EXPERIMENTAL
1604	BTRFS_ATTR_PTR(, offload_csum),
1605	#endif
1606	NULL,
1607	};
1608
1609	static void btrfs_release_fsid_kobj(struct kobject *kobj)
1610	{
1611	struct btrfs_fs_devices *fs_devs = to_fs_devs(kobj);
1612
1613	memset(&fs_devs->fsid_kobj, 0, sizeof(struct kobject));
1614	complete(&fs_devs->kobj_unregister);
1615	}
1616
1617	static const struct kobj_type btrfs_ktype = {
1618	.sysfs_ops = &kobj_sysfs_ops,
1619	.release = btrfs_release_fsid_kobj,
1620	};
1621
1622	static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj)
1623	{
1624	if (kobj->ktype != &btrfs_ktype)
1625	return NULL;
1626	return container_of(kobj, struct btrfs_fs_devices, fsid_kobj);
1627	}
1628
1629	static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)
1630	{
1631	if (kobj->ktype != &btrfs_ktype)
1632	return NULL;
1633	return to_fs_devs(kobj)->fs_info;
1634	}
1635
1636	static struct kobject *get_btrfs_kobj(struct kobject *kobj)
1637	{
1638	while (kobj) {
1639	if (kobj->ktype == &btrfs_ktype)
1640	return kobj;
1641	kobj = kobj->parent;
1642	}
1643	return NULL;
1644	}
1645
1646	#define NUM_FEATURE_BITS 64
1647	#define BTRFS_FEATURE_NAME_MAX 13
1648	static char btrfs_unknown_feature_names[FEAT_MAX][NUM_FEATURE_BITS][BTRFS_FEATURE_NAME_MAX];
1649	static struct btrfs_feature_attr btrfs_feature_attrs[FEAT_MAX][NUM_FEATURE_BITS];
1650
1651	static_assert(ARRAY_SIZE(btrfs_unknown_feature_names) ==
1652	ARRAY_SIZE(btrfs_feature_attrs));
1653	static_assert(ARRAY_SIZE(btrfs_unknown_feature_names[0]) ==
1654	ARRAY_SIZE(btrfs_feature_attrs[0]));
1655
1656	static const u64 supported_feature_masks[FEAT_MAX] = {
1657	[FEAT_COMPAT] = BTRFS_FEATURE_COMPAT_SUPP,
1658	[FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP,
1659	[FEAT_INCOMPAT] = BTRFS_FEATURE_INCOMPAT_SUPP,
1660	};
1661
1662	static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add)
1663	{
1664	int set;
1665
1666	for (set = 0; set < FEAT_MAX; set++) {
1667	int i;
1668	struct attribute *attrs[2];
1669	struct attribute_group agroup = {
1670	.name = "features",
1671	.attrs = attrs,
1672	};
1673	u64 features = get_features(fs_info, set);
1674	features &= ~supported_feature_masks[set];
1675
1676	if (!features)
1677	continue;
1678
1679	attrs[1] = NULL;
1680	for (i = 0; i < NUM_FEATURE_BITS; i++) {
1681	struct btrfs_feature_attr *fa;
1682
1683	if (!(features & (1ULL << i)))
1684	continue;
1685
1686	fa = &btrfs_feature_attrs[set][i];
1687	attrs[0] = &fa->kobj_attr.attr;
1688	if (add) {
1689	int ret;
1690	ret = sysfs_merge_group(kobj: &fs_info->fs_devices->fsid_kobj,
1691	grp: &agroup);
1692	if (ret)
1693	return ret;
1694	} else
1695	sysfs_unmerge_group(kobj: &fs_info->fs_devices->fsid_kobj,
1696	grp: &agroup);
1697	}
1698
1699	}
1700	return 0;
1701	}
1702
1703	static void __btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1704	{
1705	if (fs_devs->devinfo_kobj) {
1706	kobject_del(kobj: fs_devs->devinfo_kobj);
1707	kobject_put(kobj: fs_devs->devinfo_kobj);
1708	fs_devs->devinfo_kobj = NULL;
1709	}
1710
1711	if (fs_devs->devices_kobj) {
1712	kobject_del(kobj: fs_devs->devices_kobj);
1713	kobject_put(kobj: fs_devs->devices_kobj);
1714	fs_devs->devices_kobj = NULL;
1715	}
1716
1717	if (fs_devs->fsid_kobj.state_initialized) {
1718	kobject_del(kobj: &fs_devs->fsid_kobj);
1719	kobject_put(kobj: &fs_devs->fsid_kobj);
1720	wait_for_completion(&fs_devs->kobj_unregister);
1721	}
1722	}
1723
1724	/* when fs_devs is NULL it will remove all fsid kobject */
1725	void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1726	{
1727	struct list_head *fs_uuids = btrfs_get_fs_uuids();
1728
1729	if (fs_devs) {
1730	__btrfs_sysfs_remove_fsid(fs_devs);
1731	return;
1732	}
1733
1734	list_for_each_entry(fs_devs, fs_uuids, fs_list) {
1735	__btrfs_sysfs_remove_fsid(fs_devs);
1736	}
1737	}
1738
1739	static void btrfs_sysfs_remove_fs_devices(struct btrfs_fs_devices *fs_devices)
1740	{
1741	struct btrfs_device *device;
1742	struct btrfs_fs_devices *seed;
1743
1744	list_for_each_entry(device, &fs_devices->devices, dev_list)
1745	btrfs_sysfs_remove_device(device);
1746
1747	list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
1748	list_for_each_entry(device, &seed->devices, dev_list)
1749	btrfs_sysfs_remove_device(device);
1750	}
1751	}
1752
1753	void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info)
1754	{
1755	struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
1756
1757	sysfs_remove_link(kobj: fsid_kobj, name: "bdi");
1758
1759	if (fs_info->space_info_kobj) {
1760	sysfs_remove_files(kobj: fs_info->space_info_kobj, attr: allocation_attrs);
1761	kobject_del(kobj: fs_info->space_info_kobj);
1762	kobject_put(kobj: fs_info->space_info_kobj);
1763	}
1764	if (fs_info->discard_kobj) {
1765	sysfs_remove_files(kobj: fs_info->discard_kobj, attr: discard_attrs);
1766	kobject_del(kobj: fs_info->discard_kobj);
1767	kobject_put(kobj: fs_info->discard_kobj);
1768	}
1769	#ifdef CONFIG_BTRFS_DEBUG
1770	if (fs_info->debug_kobj) {
1771	sysfs_remove_files(kobj: fs_info->debug_kobj, attr: btrfs_debug_mount_attrs);
1772	kobject_del(kobj: fs_info->debug_kobj);
1773	kobject_put(kobj: fs_info->debug_kobj);
1774	}
1775	#endif
1776	addrm_unknown_feature_attrs(fs_info, add: false);
1777	sysfs_remove_group(kobj: fsid_kobj, grp: &btrfs_feature_attr_group);
1778	sysfs_remove_files(kobj: fsid_kobj, attr: btrfs_attrs);
1779	btrfs_sysfs_remove_fs_devices(fs_devices: fs_info->fs_devices);
1780	}
1781
1782	static const char * const btrfs_feature_set_names[FEAT_MAX] = {
1783	[FEAT_COMPAT] = "compat",
1784	[FEAT_COMPAT_RO] = "compat_ro",
1785	[FEAT_INCOMPAT] = "incompat",
1786	};
1787
1788	const char *btrfs_feature_set_name(enum btrfs_feature_set set)
1789	{
1790	return btrfs_feature_set_names[set];
1791	}
1792
1793	char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags)
1794	{
1795	size_t bufsize = 4096; /* safe max, 64 names * 64 bytes */
1796	int len = 0;
1797	int i;
1798	char *str;
1799
1800	str = kmalloc(bufsize, GFP_KERNEL);
1801	if (!str)
1802	return str;
1803
1804	for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1805	const char *name;
1806
1807	if (!(flags & (1ULL << i)))
1808	continue;
1809
1810	name = btrfs_feature_attrs[set][i].kobj_attr.attr.name;
1811	len += scnprintf(buf: str + len, size: bufsize - len, fmt: "%s%s",
1812	len ? "," : "", name);
1813	}
1814
1815	return str;
1816	}
1817
1818	static void init_feature_attrs(void)
1819	{
1820	struct btrfs_feature_attr *fa;
1821	int set, i;
1822
1823	memset(btrfs_feature_attrs, 0, sizeof(btrfs_feature_attrs));
1824	memset(btrfs_unknown_feature_names, 0,
1825	sizeof(btrfs_unknown_feature_names));
1826
1827	for (i = 0; btrfs_supported_feature_attrs[i]; i++) {
1828	struct btrfs_feature_attr *sfa;
1829	struct attribute *a = btrfs_supported_feature_attrs[i];
1830	int bit;
1831	sfa = attr_to_btrfs_feature_attr(attr: a);
1832	bit = ilog2(sfa->feature_bit);
1833	fa = &btrfs_feature_attrs[sfa->feature_set][bit];
1834
1835	fa->kobj_attr.attr.name = sfa->kobj_attr.attr.name;
1836	}
1837
1838	for (set = 0; set < FEAT_MAX; set++) {
1839	for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1840	char *name = btrfs_unknown_feature_names[set][i];
1841	fa = &btrfs_feature_attrs[set][i];
1842
1843	if (fa->kobj_attr.attr.name)
1844	continue;
1845
1846	snprintf(buf: name, BTRFS_FEATURE_NAME_MAX, fmt: "%s:%u",
1847	btrfs_feature_set_names[set], i);
1848
1849	fa->kobj_attr.attr.name = name;
1850	fa->kobj_attr.attr.mode = S_IRUGO;
1851	fa->feature_set = set;
1852	fa->feature_bit = 1ULL << i;
1853	}
1854	}
1855	}
1856
1857	/*
1858	* Create a sysfs entry for a given block group type at path
1859	* /sys/fs/btrfs/UUID/allocation/data/TYPE
1860	*/
1861	void btrfs_sysfs_add_block_group_type(struct btrfs_block_group *cache)
1862	{
1863	struct btrfs_fs_info *fs_info = cache->fs_info;
1864	struct btrfs_space_info *space_info = cache->space_info;
1865	struct raid_kobject *rkobj;
1866	const int index = btrfs_bg_flags_to_raid_index(flags: cache->flags);
1867	unsigned int nofs_flag;
1868	int ret;
1869
1870	/*
1871	* Setup a NOFS context because kobject_add(), deep in its call chain,
1872	* does GFP_KERNEL allocations, and we are often called in a context
1873	* where if reclaim is triggered we can deadlock (we are either holding
1874	* a transaction handle or some lock required for a transaction
1875	* commit).
1876	*/
1877	nofs_flag = memalloc_nofs_save();
1878
1879	rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS);
1880	if (!rkobj) {
1881	memalloc_nofs_restore(flags: nofs_flag);
1882	btrfs_warn(cache->fs_info,
1883	"couldn't alloc memory for raid level kobject");
1884	return;
1885	}
1886
1887	rkobj->flags = cache->flags;
1888	kobject_init(kobj: &rkobj->kobj, ktype: &btrfs_raid_ktype);
1889
1890	/*
1891	* We call this either on mount, or if we've created a block group for a
1892	* new index type while running (i.e. when restriping). The running
1893	* case is tricky because we could race with other threads, so we need
1894	* to have this check to make sure we didn't already init the kobject.
1895	*
1896	* We don't have to protect on the free side because it only happens on
1897	* unmount.
1898	*/
1899	spin_lock(lock: &space_info->lock);
1900	if (space_info->block_group_kobjs[index]) {
1901	spin_unlock(lock: &space_info->lock);
1902	kobject_put(kobj: &rkobj->kobj);
1903	return;
1904	} else {
1905	space_info->block_group_kobjs[index] = &rkobj->kobj;
1906	}
1907	spin_unlock(lock: &space_info->lock);
1908
1909	ret = kobject_add(kobj: &rkobj->kobj, parent: &space_info->kobj, fmt: "%s",
1910	btrfs_bg_type_to_raid_name(flags: rkobj->flags));
1911	memalloc_nofs_restore(flags: nofs_flag);
1912	if (ret) {
1913	spin_lock(lock: &space_info->lock);
1914	space_info->block_group_kobjs[index] = NULL;
1915	spin_unlock(lock: &space_info->lock);
1916	kobject_put(kobj: &rkobj->kobj);
1917	btrfs_warn(fs_info,
1918	"failed to add kobject for block cache, ignoring");
1919	return;
1920	}
1921	}
1922
1923	/*
1924	* Remove sysfs directories for all block group types of a given space info and
1925	* the space info as well
1926	*/
1927	void btrfs_sysfs_remove_space_info(struct btrfs_space_info *space_info)
1928	{
1929	int i;
1930
1931	for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
1932	struct kobject *kobj;
1933
1934	kobj = space_info->block_group_kobjs[i];
1935	space_info->block_group_kobjs[i] = NULL;
1936	if (kobj) {
1937	kobject_del(kobj);
1938	kobject_put(kobj);
1939	}
1940	}
1941	kobject_del(kobj: &space_info->kobj);
1942	kobject_put(kobj: &space_info->kobj);
1943	}
1944
1945	static const char *alloc_name(struct btrfs_space_info *space_info)
1946	{
1947	u64 flags = space_info->flags;
1948
1949	switch (flags) {
1950	case BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA:
1951	return "mixed";
1952	case BTRFS_BLOCK_GROUP_METADATA:
1953	switch (space_info->subgroup_id) {
1954	case BTRFS_SUB_GROUP_PRIMARY:
1955	return "metadata";
1956	case BTRFS_SUB_GROUP_TREELOG:
1957	return "metadata-treelog";
1958	default:
1959	WARN_ON_ONCE(1);
1960	return "metadata (unknown sub-group)";
1961	}
1962	case BTRFS_BLOCK_GROUP_DATA:
1963	switch (space_info->subgroup_id) {
1964	case BTRFS_SUB_GROUP_PRIMARY:
1965	return "data";
1966	case BTRFS_SUB_GROUP_DATA_RELOC:
1967	return "data-reloc";
1968	default:
1969	WARN_ON_ONCE(1);
1970	return "data (unknown sub-group)";
1971	}
1972	case BTRFS_BLOCK_GROUP_SYSTEM:
1973	ASSERT(space_info->subgroup_id == BTRFS_SUB_GROUP_PRIMARY);
1974	return "system";
1975	default:
1976	WARN_ON(1);
1977	return "invalid-combination";
1978	}
1979	}
1980
1981	/*
1982	* Create a sysfs entry for a space info type at path
1983	* /sys/fs/btrfs/UUID/allocation/TYPE
1984	*/
1985	int btrfs_sysfs_add_space_info_type(struct btrfs_space_info *space_info)
1986	{
1987	int ret;
1988
1989	ret = kobject_init_and_add(kobj: &space_info->kobj, ktype: &space_info_ktype,
1990	parent: space_info->fs_info->space_info_kobj, fmt: "%s",
1991	alloc_name(space_info));
1992	if (ret) {
1993	kobject_put(kobj: &space_info->kobj);
1994	return ret;
1995	}
1996
1997	return 0;
1998	}
1999
2000	void btrfs_sysfs_remove_device(struct btrfs_device *device)
2001	{
2002	struct kobject *devices_kobj;
2003
2004	/*
2005	* Seed fs_devices devices_kobj aren't used, fetch kobject from the
2006	* fs_info::fs_devices.
2007	*/
2008	devices_kobj = device->fs_info->fs_devices->devices_kobj;
2009	ASSERT(devices_kobj);
2010
2011	if (device->bdev)
2012	sysfs_remove_link(kobj: devices_kobj, bdev_kobj(device->bdev)->name);
2013
2014	if (device->devid_kobj.state_initialized) {
2015	kobject_del(kobj: &device->devid_kobj);
2016	kobject_put(kobj: &device->devid_kobj);
2017	wait_for_completion(&device->kobj_unregister);
2018	}
2019	}
2020
2021	static ssize_t btrfs_devinfo_in_fs_metadata_show(struct kobject *kobj,
2022	struct kobj_attribute *a,
2023	char *buf)
2024	{
2025	int val;
2026	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
2027	devid_kobj);
2028
2029	val = !!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
2030
2031	return sysfs_emit(buf, fmt: "%d\n", val);
2032	}
2033	BTRFS_ATTR(devid, in_fs_metadata, btrfs_devinfo_in_fs_metadata_show);
2034
2035	static ssize_t btrfs_devinfo_missing_show(struct kobject *kobj,
2036	struct kobj_attribute *a, char *buf)
2037	{
2038	int val;
2039	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
2040	devid_kobj);
2041
2042	val = !!test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state);
2043
2044	return sysfs_emit(buf, fmt: "%d\n", val);
2045	}
2046	BTRFS_ATTR(devid, missing, btrfs_devinfo_missing_show);
2047
2048	static ssize_t btrfs_devinfo_replace_target_show(struct kobject *kobj,
2049	struct kobj_attribute *a,
2050	char *buf)
2051	{
2052	int val;
2053	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
2054	devid_kobj);
2055
2056	val = !!test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state);
2057
2058	return sysfs_emit(buf, fmt: "%d\n", val);
2059	}
2060	BTRFS_ATTR(devid, replace_target, btrfs_devinfo_replace_target_show);
2061
2062	static ssize_t btrfs_devinfo_scrub_speed_max_show(struct kobject *kobj,
2063	struct kobj_attribute *a,
2064	char *buf)
2065	{
2066	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
2067	devid_kobj);
2068
2069	return sysfs_emit(buf, fmt: "%llu\n", READ_ONCE(device->scrub_speed_max));
2070	}
2071
2072	static ssize_t btrfs_devinfo_scrub_speed_max_store(struct kobject *kobj,
2073	struct kobj_attribute *a,
2074	const char *buf, size_t len)
2075	{
2076	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
2077	devid_kobj);
2078	char *endptr;
2079	unsigned long long limit;
2080
2081	limit = memparse(ptr: buf, retptr: &endptr);
2082	/* There could be trailing '\n', also catch any typos after the value. */
2083	endptr = skip_spaces(endptr);
2084	if (*endptr != 0)
2085	return -EINVAL;
2086	WRITE_ONCE(device->scrub_speed_max, limit);
2087	return len;
2088	}
2089	BTRFS_ATTR_RW(devid, scrub_speed_max, btrfs_devinfo_scrub_speed_max_show,
2090	btrfs_devinfo_scrub_speed_max_store);
2091
2092	static ssize_t btrfs_devinfo_writeable_show(struct kobject *kobj,
2093	struct kobj_attribute *a, char *buf)
2094	{
2095	int val;
2096	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
2097	devid_kobj);
2098
2099	val = !!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
2100
2101	return sysfs_emit(buf, fmt: "%d\n", val);
2102	}
2103	BTRFS_ATTR(devid, writeable, btrfs_devinfo_writeable_show);
2104
2105	static ssize_t btrfs_devinfo_fsid_show(struct kobject *kobj,
2106	struct kobj_attribute *a, char *buf)
2107	{
2108	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
2109	devid_kobj);
2110
2111	return sysfs_emit(buf, fmt: "%pU\n", device->fs_devices->fsid);
2112	}
2113	BTRFS_ATTR(devid, fsid, btrfs_devinfo_fsid_show);
2114
2115	static ssize_t btrfs_devinfo_error_stats_show(struct kobject *kobj,
2116	struct kobj_attribute *a, char *buf)
2117	{
2118	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
2119	devid_kobj);
2120
2121	if (!device->dev_stats_valid)
2122	return sysfs_emit(buf, fmt: "invalid\n");
2123
2124	/*
2125	* Print all at once so we get a snapshot of all values from the same
2126	* time. Keep them in sync and in order of definition of
2127	* btrfs_dev_stat_values.
2128	*/
2129	return sysfs_emit(buf,
2130	fmt: "write_errs %d\n"
2131	"read_errs %d\n"
2132	"flush_errs %d\n"
2133	"corruption_errs %d\n"
2134	"generation_errs %d\n",
2135	btrfs_dev_stat_read(dev: device, index: BTRFS_DEV_STAT_WRITE_ERRS),
2136	btrfs_dev_stat_read(dev: device, index: BTRFS_DEV_STAT_READ_ERRS),
2137	btrfs_dev_stat_read(dev: device, index: BTRFS_DEV_STAT_FLUSH_ERRS),
2138	btrfs_dev_stat_read(dev: device, index: BTRFS_DEV_STAT_CORRUPTION_ERRS),
2139	btrfs_dev_stat_read(dev: device, index: BTRFS_DEV_STAT_GENERATION_ERRS));
2140	}
2141	BTRFS_ATTR(devid, error_stats, btrfs_devinfo_error_stats_show);
2142
2143	/*
2144	* Information about one device.
2145	*
2146	* Path: /sys/fs/btrfs/<uuid>/devinfo/<devid>/
2147	*/
2148	static struct attribute *devid_attrs[] = {
2149	BTRFS_ATTR_PTR(devid, error_stats),
2150	BTRFS_ATTR_PTR(devid, fsid),
2151	BTRFS_ATTR_PTR(devid, in_fs_metadata),
2152	BTRFS_ATTR_PTR(devid, missing),
2153	BTRFS_ATTR_PTR(devid, replace_target),
2154	BTRFS_ATTR_PTR(devid, scrub_speed_max),
2155	BTRFS_ATTR_PTR(devid, writeable),
2156	NULL
2157	};
2158	ATTRIBUTE_GROUPS(devid);
2159
2160	static void btrfs_release_devid_kobj(struct kobject *kobj)
2161	{
2162	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
2163	devid_kobj);
2164
2165	memset(&device->devid_kobj, 0, sizeof(struct kobject));
2166	complete(&device->kobj_unregister);
2167	}
2168
2169	static const struct kobj_type devid_ktype = {
2170	.sysfs_ops = &kobj_sysfs_ops,
2171	.default_groups = devid_groups,
2172	.release = btrfs_release_devid_kobj,
2173	};
2174
2175	int btrfs_sysfs_add_device(struct btrfs_device *device)
2176	{
2177	int ret;
2178	unsigned int nofs_flag;
2179	struct kobject *devices_kobj;
2180	struct kobject *devinfo_kobj;
2181
2182	/*
2183	* Make sure we use the fs_info::fs_devices to fetch the kobjects even
2184	* for the seed fs_devices
2185	*/
2186	devices_kobj = device->fs_info->fs_devices->devices_kobj;
2187	devinfo_kobj = device->fs_info->fs_devices->devinfo_kobj;
2188	ASSERT(devices_kobj);
2189	ASSERT(devinfo_kobj);
2190
2191	nofs_flag = memalloc_nofs_save();
2192
2193	if (device->bdev) {
2194	struct kobject *disk_kobj = bdev_kobj(device->bdev);
2195
2196	ret = sysfs_create_link(kobj: devices_kobj, target: disk_kobj, name: disk_kobj->name);
2197	if (ret) {
2198	btrfs_warn(device->fs_info,
2199	"creating sysfs device link for devid %llu failed: %d",
2200	device->devid, ret);
2201	goto out;
2202	}
2203	}
2204
2205	init_completion(x: &device->kobj_unregister);
2206	ret = kobject_init_and_add(kobj: &device->devid_kobj, ktype: &devid_ktype,
2207	parent: devinfo_kobj, fmt: "%llu", device->devid);
2208	if (ret) {
2209	kobject_put(kobj: &device->devid_kobj);
2210	btrfs_warn(device->fs_info,
2211	"devinfo init for devid %llu failed: %d",
2212	device->devid, ret);
2213	}
2214
2215	out:
2216	memalloc_nofs_restore(flags: nofs_flag);
2217	return ret;
2218	}
2219
2220	static int btrfs_sysfs_add_fs_devices(struct btrfs_fs_devices *fs_devices)
2221	{
2222	int ret;
2223	struct btrfs_device *device;
2224	struct btrfs_fs_devices *seed;
2225
2226	list_for_each_entry(device, &fs_devices->devices, dev_list) {
2227	ret = btrfs_sysfs_add_device(device);
2228	if (ret)
2229	goto fail;
2230	}
2231
2232	list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
2233	list_for_each_entry(device, &seed->devices, dev_list) {
2234	ret = btrfs_sysfs_add_device(device);
2235	if (ret)
2236	goto fail;
2237	}
2238	}
2239
2240	return 0;
2241
2242	fail:
2243	btrfs_sysfs_remove_fs_devices(fs_devices);
2244	return ret;
2245	}
2246
2247	void btrfs_kobject_uevent(struct block_device *bdev, enum kobject_action action)
2248	{
2249	int ret;
2250
2251	ret = kobject_uevent(kobj: &disk_to_dev(bdev->bd_disk)->kobj, action);
2252	if (ret)
2253	btrfs_warn(NULL, "sending event %d to kobject: '%s' (%p): failed",
2254	action, kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
2255	&disk_to_dev(bdev->bd_disk)->kobj);
2256	}
2257
2258	void btrfs_sysfs_update_sprout_fsid(struct btrfs_fs_devices *fs_devices)
2259
2260	{
2261	char fsid_buf[BTRFS_UUID_UNPARSED_SIZE];
2262
2263	/*
2264	* Sprouting changes fsid of the mounted filesystem, rename the fsid
2265	* directory
2266	*/
2267	snprintf(buf: fsid_buf, BTRFS_UUID_UNPARSED_SIZE, fmt: "%pU", fs_devices->fsid);
2268	if (kobject_rename(&fs_devices->fsid_kobj, new_name: fsid_buf))
2269	btrfs_warn(fs_devices->fs_info,
2270	"sysfs: failed to create fsid for sprout");
2271	}
2272
2273	void btrfs_sysfs_update_devid(struct btrfs_device *device)
2274	{
2275	char tmp[24];
2276
2277	snprintf(buf: tmp, size: sizeof(tmp), fmt: "%llu", device->devid);
2278
2279	if (kobject_rename(&device->devid_kobj, new_name: tmp))
2280	btrfs_warn(device->fs_devices->fs_info,
2281	"sysfs: failed to update devid for %llu",
2282	device->devid);
2283	}
2284
2285	/* /sys/fs/btrfs/ entry */
2286	static struct kset *btrfs_kset;
2287
2288	/*
2289	* Creates:
2290	* /sys/fs/btrfs/UUID
2291	*
2292	* Can be called by the device discovery thread.
2293	*/
2294	int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs)
2295	{
2296	int ret;
2297
2298	init_completion(x: &fs_devs->kobj_unregister);
2299	fs_devs->fsid_kobj.kset = btrfs_kset;
2300	ret = kobject_init_and_add(kobj: &fs_devs->fsid_kobj, ktype: &btrfs_ktype, NULL,
2301	fmt: "%pU", fs_devs->fsid);
2302	if (ret) {
2303	kobject_put(kobj: &fs_devs->fsid_kobj);
2304	return ret;
2305	}
2306
2307	fs_devs->devices_kobj = kobject_create_and_add(name: "devices",
2308	parent: &fs_devs->fsid_kobj);
2309	if (!fs_devs->devices_kobj) {
2310	btrfs_err(fs_devs->fs_info,
2311	"failed to init sysfs device interface");
2312	btrfs_sysfs_remove_fsid(fs_devs);
2313	return -ENOMEM;
2314	}
2315
2316	fs_devs->devinfo_kobj = kobject_create_and_add(name: "devinfo",
2317	parent: &fs_devs->fsid_kobj);
2318	if (!fs_devs->devinfo_kobj) {
2319	btrfs_err(fs_devs->fs_info,
2320	"failed to init sysfs devinfo kobject");
2321	btrfs_sysfs_remove_fsid(fs_devs);
2322	return -ENOMEM;
2323	}
2324
2325	return 0;
2326	}
2327
2328	int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info)
2329	{
2330	int ret;
2331	struct btrfs_fs_devices *fs_devs = fs_info->fs_devices;
2332	struct kobject *fsid_kobj = &fs_devs->fsid_kobj;
2333
2334	ret = btrfs_sysfs_add_fs_devices(fs_devices: fs_devs);
2335	if (ret)
2336	return ret;
2337
2338	ret = sysfs_create_files(kobj: fsid_kobj, attr: btrfs_attrs);
2339	if (ret) {
2340	btrfs_sysfs_remove_fs_devices(fs_devices: fs_devs);
2341	return ret;
2342	}
2343
2344	ret = sysfs_create_group(kobj: fsid_kobj, grp: &btrfs_feature_attr_group);
2345	if (ret)
2346	goto failure;
2347
2348	#ifdef CONFIG_BTRFS_DEBUG
2349	fs_info->debug_kobj = kobject_create_and_add(name: "debug", parent: fsid_kobj);
2350	if (!fs_info->debug_kobj) {
2351	ret = -ENOMEM;
2352	goto failure;
2353	}
2354
2355	ret = sysfs_create_files(kobj: fs_info->debug_kobj, attr: btrfs_debug_mount_attrs);
2356	if (ret)
2357	goto failure;
2358	#endif
2359
2360	/* Discard directory */
2361	fs_info->discard_kobj = kobject_create_and_add(name: "discard", parent: fsid_kobj);
2362	if (!fs_info->discard_kobj) {
2363	ret = -ENOMEM;
2364	goto failure;
2365	}
2366
2367	ret = sysfs_create_files(kobj: fs_info->discard_kobj, attr: discard_attrs);
2368	if (ret)
2369	goto failure;
2370
2371	ret = addrm_unknown_feature_attrs(fs_info, add: true);
2372	if (ret)
2373	goto failure;
2374
2375	ret = sysfs_create_link(kobj: fsid_kobj, target: &fs_info->sb->s_bdi->dev->kobj, name: "bdi");
2376	if (ret)
2377	goto failure;
2378
2379	fs_info->space_info_kobj = kobject_create_and_add(name: "allocation",
2380	parent: fsid_kobj);
2381	if (!fs_info->space_info_kobj) {
2382	ret = -ENOMEM;
2383	goto failure;
2384	}
2385
2386	ret = sysfs_create_files(kobj: fs_info->space_info_kobj, attr: allocation_attrs);
2387	if (ret)
2388	goto failure;
2389
2390	return 0;
2391	failure:
2392	btrfs_sysfs_remove_mounted(fs_info);
2393	return ret;
2394	}
2395
2396	static ssize_t qgroup_enabled_show(struct kobject *qgroups_kobj,
2397	struct kobj_attribute *a,
2398	char *buf)
2399	{
2400	struct btrfs_fs_info *fs_info = to_fs_info(kobj: qgroups_kobj->parent);
2401	bool enabled;
2402
2403	spin_lock(lock: &fs_info->qgroup_lock);
2404	enabled = fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON;
2405	spin_unlock(lock: &fs_info->qgroup_lock);
2406
2407	return sysfs_emit(buf, fmt: "%d\n", enabled);
2408	}
2409	BTRFS_ATTR(qgroups, enabled, qgroup_enabled_show);
2410
2411	static ssize_t qgroup_mode_show(struct kobject *qgroups_kobj,
2412	struct kobj_attribute *a,
2413	char *buf)
2414	{
2415	struct btrfs_fs_info *fs_info = to_fs_info(kobj: qgroups_kobj->parent);
2416	ssize_t ret = 0;
2417
2418	spin_lock(lock: &fs_info->qgroup_lock);
2419	ASSERT(btrfs_qgroup_enabled(fs_info));
2420	switch (btrfs_qgroup_mode(fs_info)) {
2421	case BTRFS_QGROUP_MODE_FULL:
2422	ret = sysfs_emit(buf, fmt: "qgroup\n");
2423	break;
2424	case BTRFS_QGROUP_MODE_SIMPLE:
2425	ret = sysfs_emit(buf, fmt: "squota\n");
2426	break;
2427	default:
2428	btrfs_warn(fs_info, "unexpected qgroup mode %d\n",
2429	btrfs_qgroup_mode(fs_info));
2430	break;
2431	}
2432	spin_unlock(lock: &fs_info->qgroup_lock);
2433
2434	return ret;
2435	}
2436	BTRFS_ATTR(qgroups, mode, qgroup_mode_show);
2437
2438	static ssize_t qgroup_inconsistent_show(struct kobject *qgroups_kobj,
2439	struct kobj_attribute *a,
2440	char *buf)
2441	{
2442	struct btrfs_fs_info *fs_info = to_fs_info(kobj: qgroups_kobj->parent);
2443	bool inconsistent;
2444
2445	spin_lock(lock: &fs_info->qgroup_lock);
2446	inconsistent = (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT);
2447	spin_unlock(lock: &fs_info->qgroup_lock);
2448
2449	return sysfs_emit(buf, fmt: "%d\n", inconsistent);
2450	}
2451	BTRFS_ATTR(qgroups, inconsistent, qgroup_inconsistent_show);
2452
2453	static ssize_t qgroup_drop_subtree_thres_show(struct kobject *qgroups_kobj,
2454	struct kobj_attribute *a,
2455	char *buf)
2456	{
2457	struct btrfs_fs_info *fs_info = to_fs_info(kobj: qgroups_kobj->parent);
2458	u8 result;
2459
2460	spin_lock(lock: &fs_info->qgroup_lock);
2461	result = fs_info->qgroup_drop_subtree_thres;
2462	spin_unlock(lock: &fs_info->qgroup_lock);
2463
2464	return sysfs_emit(buf, fmt: "%d\n", result);
2465	}
2466
2467	static ssize_t qgroup_drop_subtree_thres_store(struct kobject *qgroups_kobj,
2468	struct kobj_attribute *a,
2469	const char *buf, size_t len)
2470	{
2471	struct btrfs_fs_info *fs_info = to_fs_info(kobj: qgroups_kobj->parent);
2472	u8 new_thres;
2473	int ret;
2474
2475	ret = kstrtou8(s: buf, base: 10, res: &new_thres);
2476	if (ret)
2477	return -EINVAL;
2478
2479	if (new_thres > BTRFS_MAX_LEVEL)
2480	return -EINVAL;
2481
2482	spin_lock(lock: &fs_info->qgroup_lock);
2483	fs_info->qgroup_drop_subtree_thres = new_thres;
2484	spin_unlock(lock: &fs_info->qgroup_lock);
2485
2486	return len;
2487	}
2488	BTRFS_ATTR_RW(qgroups, drop_subtree_threshold, qgroup_drop_subtree_thres_show,
2489	qgroup_drop_subtree_thres_store);
2490
2491	/*
2492	* Qgroups global info
2493	*
2494	* Path: /sys/fs/btrfs/<uuid>/qgroups/
2495	*/
2496	static struct attribute *qgroups_attrs[] = {
2497	BTRFS_ATTR_PTR(qgroups, enabled),
2498	BTRFS_ATTR_PTR(qgroups, inconsistent),
2499	BTRFS_ATTR_PTR(qgroups, drop_subtree_threshold),
2500	BTRFS_ATTR_PTR(qgroups, mode),
2501	NULL
2502	};
2503	ATTRIBUTE_GROUPS(qgroups);
2504
2505	static void qgroups_release(struct kobject *kobj)
2506	{
2507	kfree(objp: kobj);
2508	}
2509
2510	static const struct kobj_type qgroups_ktype = {
2511	.sysfs_ops = &kobj_sysfs_ops,
2512	.default_groups = qgroups_groups,
2513	.release = qgroups_release,
2514	};
2515
2516	static inline struct btrfs_fs_info *qgroup_kobj_to_fs_info(struct kobject *kobj)
2517	{
2518	return to_fs_info(kobj: kobj->parent->parent);
2519	}
2520
2521	#define QGROUP_ATTR(_member, _show_name) \
2522	static ssize_t btrfs_qgroup_show_##_member(struct kobject *qgroup_kobj, \
2523	struct kobj_attribute *a, \
2524	char *buf) \
2525	{ \
2526	struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj); \
2527	struct btrfs_qgroup *qgroup = container_of(qgroup_kobj, \
2528	struct btrfs_qgroup, kobj); \
2529	return btrfs_show_u64(&qgroup->_member, &fs_info->qgroup_lock, buf); \
2530	} \
2531	BTRFS_ATTR(qgroup, _show_name, btrfs_qgroup_show_##_member)
2532
2533	#define QGROUP_RSV_ATTR(_name, _type) \
2534	static ssize_t btrfs_qgroup_rsv_show_##_name(struct kobject *qgroup_kobj, \
2535	struct kobj_attribute *a, \
2536	char *buf) \
2537	{ \
2538	struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj); \
2539	struct btrfs_qgroup *qgroup = container_of(qgroup_kobj, \
2540	struct btrfs_qgroup, kobj); \
2541	return btrfs_show_u64(&qgroup->rsv.values[_type], \
2542	&fs_info->qgroup_lock, buf); \
2543	} \
2544	BTRFS_ATTR(qgroup, rsv_##_name, btrfs_qgroup_rsv_show_##_name)
2545
2546	QGROUP_ATTR(rfer, referenced);
2547	QGROUP_ATTR(excl, exclusive);
2548	QGROUP_ATTR(max_rfer, max_referenced);
2549	QGROUP_ATTR(max_excl, max_exclusive);
2550	QGROUP_ATTR(lim_flags, limit_flags);
2551	QGROUP_RSV_ATTR(data, BTRFS_QGROUP_RSV_DATA);
2552	QGROUP_RSV_ATTR(meta_pertrans, BTRFS_QGROUP_RSV_META_PERTRANS);
2553	QGROUP_RSV_ATTR(meta_prealloc, BTRFS_QGROUP_RSV_META_PREALLOC);
2554
2555	/*
2556	* Qgroup information.
2557	*
2558	* Path: /sys/fs/btrfs/<uuid>/qgroups/<level>_<qgroupid>/
2559	*/
2560	static struct attribute *qgroup_attrs[] = {
2561	BTRFS_ATTR_PTR(qgroup, referenced),
2562	BTRFS_ATTR_PTR(qgroup, exclusive),
2563	BTRFS_ATTR_PTR(qgroup, max_referenced),
2564	BTRFS_ATTR_PTR(qgroup, max_exclusive),
2565	BTRFS_ATTR_PTR(qgroup, limit_flags),
2566	BTRFS_ATTR_PTR(qgroup, rsv_data),
2567	BTRFS_ATTR_PTR(qgroup, rsv_meta_pertrans),
2568	BTRFS_ATTR_PTR(qgroup, rsv_meta_prealloc),
2569	NULL
2570	};
2571	ATTRIBUTE_GROUPS(qgroup);
2572
2573	static void qgroup_release(struct kobject *kobj)
2574	{
2575	struct btrfs_qgroup *qgroup = container_of(kobj, struct btrfs_qgroup, kobj);
2576
2577	memset(&qgroup->kobj, 0, sizeof(*kobj));
2578	}
2579
2580	static const struct kobj_type qgroup_ktype = {
2581	.sysfs_ops = &kobj_sysfs_ops,
2582	.release = qgroup_release,
2583	.default_groups = qgroup_groups,
2584	};
2585
2586	int btrfs_sysfs_add_one_qgroup(struct btrfs_fs_info *fs_info,
2587	struct btrfs_qgroup *qgroup)
2588	{
2589	struct kobject *qgroups_kobj = fs_info->qgroups_kobj;
2590	int ret;
2591
2592	if (btrfs_is_testing(fs_info))
2593	return 0;
2594	if (qgroup->kobj.state_initialized)
2595	return 0;
2596	if (!qgroups_kobj)
2597	return -EINVAL;
2598
2599	ret = kobject_init_and_add(kobj: &qgroup->kobj, ktype: &qgroup_ktype, parent: qgroups_kobj,
2600	fmt: "%hu_%llu", btrfs_qgroup_level(qgroupid: qgroup->qgroupid),
2601	btrfs_qgroup_subvolid(qgroupid: qgroup->qgroupid));
2602	if (ret < 0)
2603	kobject_put(kobj: &qgroup->kobj);
2604
2605	return ret;
2606	}
2607
2608	void btrfs_sysfs_del_qgroups(struct btrfs_fs_info *fs_info)
2609	{
2610	struct btrfs_qgroup *qgroup;
2611	struct btrfs_qgroup *next;
2612
2613	if (btrfs_is_testing(fs_info))
2614	return;
2615
2616	rbtree_postorder_for_each_entry_safe(qgroup, next,
2617	&fs_info->qgroup_tree, node)
2618	btrfs_sysfs_del_one_qgroup(fs_info, qgroup);
2619	if (fs_info->qgroups_kobj) {
2620	kobject_del(kobj: fs_info->qgroups_kobj);
2621	kobject_put(kobj: fs_info->qgroups_kobj);
2622	fs_info->qgroups_kobj = NULL;
2623	}
2624	}
2625
2626	/* Called when qgroups get initialized, thus there is no need for locking */
2627	int btrfs_sysfs_add_qgroups(struct btrfs_fs_info *fs_info)
2628	{
2629	struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
2630	struct btrfs_qgroup *qgroup;
2631	struct btrfs_qgroup *next;
2632	int ret = 0;
2633
2634	if (btrfs_is_testing(fs_info))
2635	return 0;
2636
2637	ASSERT(fsid_kobj);
2638	if (fs_info->qgroups_kobj)
2639	return 0;
2640
2641	fs_info->qgroups_kobj = kzalloc(sizeof(struct kobject), GFP_KERNEL);
2642	if (!fs_info->qgroups_kobj)
2643	return -ENOMEM;
2644
2645	ret = kobject_init_and_add(kobj: fs_info->qgroups_kobj, ktype: &qgroups_ktype,
2646	parent: fsid_kobj, fmt: "qgroups");
2647	if (ret < 0)
2648	goto out;
2649
2650	rbtree_postorder_for_each_entry_safe(qgroup, next,
2651	&fs_info->qgroup_tree, node) {
2652	ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
2653	if (ret < 0)
2654	goto out;
2655	}
2656
2657	out:
2658	if (ret < 0)
2659	btrfs_sysfs_del_qgroups(fs_info);
2660	return ret;
2661	}
2662
2663	void btrfs_sysfs_del_one_qgroup(struct btrfs_fs_info *fs_info,
2664	struct btrfs_qgroup *qgroup)
2665	{
2666	if (btrfs_is_testing(fs_info))
2667	return;
2668
2669	if (qgroup->kobj.state_initialized) {
2670	kobject_del(kobj: &qgroup->kobj);
2671	kobject_put(kobj: &qgroup->kobj);
2672	}
2673	}
2674
2675	/*
2676	* Change per-fs features in /sys/fs/btrfs/UUID/features to match current
2677	* values in superblock. Call after any changes to incompat/compat_ro flags
2678	*/
2679	void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info)
2680	{
2681	struct kobject *fsid_kobj;
2682	int ret;
2683
2684	if (!fs_info)
2685	return;
2686
2687	fsid_kobj = &fs_info->fs_devices->fsid_kobj;
2688	if (!fsid_kobj->state_initialized)
2689	return;
2690
2691	ret = sysfs_update_group(kobj: fsid_kobj, grp: &btrfs_feature_attr_group);
2692	if (ret < 0)
2693	btrfs_warn(fs_info,
2694	"failed to update /sys/fs/btrfs/%pU/features: %d",
2695	fs_info->fs_devices->fsid, ret);
2696	}
2697
2698	int __init btrfs_init_sysfs(void)
2699	{
2700	int ret;
2701
2702	btrfs_kset = kset_create_and_add(name: "btrfs", NULL, parent_kobj: fs_kobj);
2703	if (!btrfs_kset)
2704	return -ENOMEM;
2705
2706	init_feature_attrs();
2707	ret = sysfs_create_group(kobj: &btrfs_kset->kobj, grp: &btrfs_feature_attr_group);
2708	if (ret)
2709	goto out2;
2710	ret = sysfs_merge_group(kobj: &btrfs_kset->kobj,
2711	grp: &btrfs_static_feature_attr_group);
2712	if (ret)
2713	goto out_remove_group;
2714
2715	#ifdef CONFIG_BTRFS_DEBUG
2716	ret = sysfs_create_group(kobj: &btrfs_kset->kobj, grp: &btrfs_debug_feature_attr_group);
2717	if (ret) {
2718	sysfs_unmerge_group(kobj: &btrfs_kset->kobj,
2719	grp: &btrfs_static_feature_attr_group);
2720	goto out_remove_group;
2721	}
2722	#endif
2723
2724	return 0;
2725
2726	out_remove_group:
2727	sysfs_remove_group(kobj: &btrfs_kset->kobj, grp: &btrfs_feature_attr_group);
2728	out2:
2729	kset_unregister(kset: btrfs_kset);
2730
2731	return ret;
2732	}
2733
2734	void __cold btrfs_exit_sysfs(void)
2735	{
2736	sysfs_unmerge_group(kobj: &btrfs_kset->kobj,
2737	grp: &btrfs_static_feature_attr_group);
2738	sysfs_remove_group(kobj: &btrfs_kset->kobj, grp: &btrfs_feature_attr_group);
2739	#ifdef CONFIG_BTRFS_DEBUG
2740	sysfs_remove_group(kobj: &btrfs_kset->kobj, grp: &btrfs_debug_feature_attr_group);
2741	#endif
2742	kset_unregister(kset: btrfs_kset);
2743	}
2744