xref: /kernel/linux/linux-6.6/fs/btrfs/sysfs.c (revision 62306a36)
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 <crypto/hash.h>
14#include "messages.h"
15#include "ctree.h"
16#include "discard.h"
17#include "disk-io.h"
18#include "send.h"
19#include "transaction.h"
20#include "sysfs.h"
21#include "volumes.h"
22#include "space-info.h"
23#include "block-group.h"
24#include "qgroup.h"
25#include "misc.h"
26#include "fs.h"
27#include "accessors.h"
28
29/*
30 * Structure name                       Path
31 * --------------------------------------------------------------------------
32 * btrfs_supported_static_feature_attrs /sys/fs/btrfs/features
33 * btrfs_supported_feature_attrs	/sys/fs/btrfs/features and
34 *					/sys/fs/btrfs/<uuid>/features
35 * btrfs_attrs				/sys/fs/btrfs/<uuid>
36 * devid_attrs				/sys/fs/btrfs/<uuid>/devinfo/<devid>
37 * allocation_attrs			/sys/fs/btrfs/<uuid>/allocation
38 * qgroup_attrs				/sys/fs/btrfs/<uuid>/qgroups/<level>_<qgroupid>
39 * space_info_attrs			/sys/fs/btrfs/<uuid>/allocation/<bg-type>
40 * raid_attrs				/sys/fs/btrfs/<uuid>/allocation/<bg-type>/<bg-profile>
41 * discard_attrs			/sys/fs/btrfs/<uuid>/discard
42 *
43 * When built with BTRFS_CONFIG_DEBUG:
44 *
45 * btrfs_debug_feature_attrs		/sys/fs/btrfs/debug
46 * btrfs_debug_mount_attrs		/sys/fs/btrfs/<uuid>/debug
47 */
48
49struct btrfs_feature_attr {
50	struct kobj_attribute kobj_attr;
51	enum btrfs_feature_set feature_set;
52	u64 feature_bit;
53};
54
55/* For raid type sysfs entries */
56struct raid_kobject {
57	u64 flags;
58	struct kobject kobj;
59};
60
61#define __INIT_KOBJ_ATTR(_name, _mode, _show, _store)			\
62{									\
63	.attr	= { .name = __stringify(_name), .mode = _mode },	\
64	.show	= _show,						\
65	.store	= _store,						\
66}
67
68#define BTRFS_ATTR_W(_prefix, _name, _store)			        \
69	static struct kobj_attribute btrfs_attr_##_prefix##_##_name =	\
70			__INIT_KOBJ_ATTR(_name, 0200, NULL, _store)
71
72#define BTRFS_ATTR_RW(_prefix, _name, _show, _store)			\
73	static struct kobj_attribute btrfs_attr_##_prefix##_##_name =	\
74			__INIT_KOBJ_ATTR(_name, 0644, _show, _store)
75
76#define BTRFS_ATTR(_prefix, _name, _show)				\
77	static struct kobj_attribute btrfs_attr_##_prefix##_##_name =	\
78			__INIT_KOBJ_ATTR(_name, 0444, _show, NULL)
79
80#define BTRFS_ATTR_PTR(_prefix, _name)					\
81	(&btrfs_attr_##_prefix##_##_name.attr)
82
83#define BTRFS_FEAT_ATTR(_name, _feature_set, _feature_prefix, _feature_bit)  \
84static struct btrfs_feature_attr btrfs_attr_features_##_name = {	     \
85	.kobj_attr = __INIT_KOBJ_ATTR(_name, S_IRUGO,			     \
86				      btrfs_feature_attr_show,		     \
87				      btrfs_feature_attr_store),	     \
88	.feature_set	= _feature_set,					     \
89	.feature_bit	= _feature_prefix ##_## _feature_bit,		     \
90}
91#define BTRFS_FEAT_ATTR_PTR(_name)					     \
92	(&btrfs_attr_features_##_name.kobj_attr.attr)
93
94#define BTRFS_FEAT_ATTR_COMPAT(name, feature) \
95	BTRFS_FEAT_ATTR(name, FEAT_COMPAT, BTRFS_FEATURE_COMPAT, feature)
96#define BTRFS_FEAT_ATTR_COMPAT_RO(name, feature) \
97	BTRFS_FEAT_ATTR(name, FEAT_COMPAT_RO, BTRFS_FEATURE_COMPAT_RO, feature)
98#define BTRFS_FEAT_ATTR_INCOMPAT(name, feature) \
99	BTRFS_FEAT_ATTR(name, FEAT_INCOMPAT, BTRFS_FEATURE_INCOMPAT, feature)
100
101static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj);
102static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj);
103static struct kobject *get_btrfs_kobj(struct kobject *kobj);
104
105static struct btrfs_feature_attr *to_btrfs_feature_attr(struct kobj_attribute *a)
106{
107	return container_of(a, struct btrfs_feature_attr, kobj_attr);
108}
109
110static struct kobj_attribute *attr_to_btrfs_attr(struct attribute *attr)
111{
112	return container_of(attr, struct kobj_attribute, attr);
113}
114
115static struct btrfs_feature_attr *attr_to_btrfs_feature_attr(
116		struct attribute *attr)
117{
118	return to_btrfs_feature_attr(attr_to_btrfs_attr(attr));
119}
120
121static u64 get_features(struct btrfs_fs_info *fs_info,
122			enum btrfs_feature_set set)
123{
124	struct btrfs_super_block *disk_super = fs_info->super_copy;
125	if (set == FEAT_COMPAT)
126		return btrfs_super_compat_flags(disk_super);
127	else if (set == FEAT_COMPAT_RO)
128		return btrfs_super_compat_ro_flags(disk_super);
129	else
130		return btrfs_super_incompat_flags(disk_super);
131}
132
133static void set_features(struct btrfs_fs_info *fs_info,
134			 enum btrfs_feature_set set, u64 features)
135{
136	struct btrfs_super_block *disk_super = fs_info->super_copy;
137	if (set == FEAT_COMPAT)
138		btrfs_set_super_compat_flags(disk_super, features);
139	else if (set == FEAT_COMPAT_RO)
140		btrfs_set_super_compat_ro_flags(disk_super, features);
141	else
142		btrfs_set_super_incompat_flags(disk_super, features);
143}
144
145static int can_modify_feature(struct btrfs_feature_attr *fa)
146{
147	int val = 0;
148	u64 set, clear;
149	switch (fa->feature_set) {
150	case FEAT_COMPAT:
151		set = BTRFS_FEATURE_COMPAT_SAFE_SET;
152		clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
153		break;
154	case FEAT_COMPAT_RO:
155		set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
156		clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
157		break;
158	case FEAT_INCOMPAT:
159		set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
160		clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
161		break;
162	default:
163		pr_warn("btrfs: sysfs: unknown feature set %d\n",
164				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
176static 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, 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, "%d\n", val);
190}
191
192static 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(fs_info->sb))
207		return -EROFS;
208
209	ret = kstrtoul(skip_spaces(buf), 0, &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, 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(&fs_info->super_lock);
243	features = get_features(fs_info, fa->feature_set);
244	if (val)
245		features |= fa->feature_bit;
246	else
247		features &= ~fa->feature_bit;
248	set_features(fs_info, fa->feature_set, features);
249	spin_unlock(&fs_info->super_lock);
250
251	/*
252	 * We don't want to do full transaction commit from inside sysfs
253	 */
254	set_bit(BTRFS_FS_NEED_TRANS_COMMIT, &fs_info->flags);
255	wake_up_process(fs_info->transaction_kthread);
256
257	return count;
258}
259
260static 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, 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
282BTRFS_FEAT_ATTR_INCOMPAT(default_subvol, DEFAULT_SUBVOL);
283BTRFS_FEAT_ATTR_INCOMPAT(mixed_groups, MIXED_GROUPS);
284BTRFS_FEAT_ATTR_INCOMPAT(compress_lzo, COMPRESS_LZO);
285BTRFS_FEAT_ATTR_INCOMPAT(compress_zstd, COMPRESS_ZSTD);
286BTRFS_FEAT_ATTR_INCOMPAT(extended_iref, EXTENDED_IREF);
287BTRFS_FEAT_ATTR_INCOMPAT(raid56, RAID56);
288BTRFS_FEAT_ATTR_INCOMPAT(skinny_metadata, SKINNY_METADATA);
289BTRFS_FEAT_ATTR_INCOMPAT(no_holes, NO_HOLES);
290BTRFS_FEAT_ATTR_INCOMPAT(metadata_uuid, METADATA_UUID);
291BTRFS_FEAT_ATTR_COMPAT_RO(free_space_tree, FREE_SPACE_TREE);
292BTRFS_FEAT_ATTR_COMPAT_RO(block_group_tree, BLOCK_GROUP_TREE);
293BTRFS_FEAT_ATTR_INCOMPAT(raid1c34, RAID1C34);
294#ifdef CONFIG_BLK_DEV_ZONED
295BTRFS_FEAT_ATTR_INCOMPAT(zoned, ZONED);
296#endif
297#ifdef CONFIG_BTRFS_DEBUG
298/* Remove once support for extent tree v2 is feature complete */
299BTRFS_FEAT_ATTR_INCOMPAT(extent_tree_v2, EXTENT_TREE_V2);
300#endif
301#ifdef CONFIG_FS_VERITY
302BTRFS_FEAT_ATTR_COMPAT_RO(verity, VERITY);
303#endif
304
305/*
306 * Features which depend on feature bits and may differ between each fs.
307 *
308 * /sys/fs/btrfs/features      - all available features implemented by this version
309 * /sys/fs/btrfs/UUID/features - features of the fs which are enabled or
310 *                               can be changed on a mounted filesystem.
311 */
312static struct attribute *btrfs_supported_feature_attrs[] = {
313	BTRFS_FEAT_ATTR_PTR(default_subvol),
314	BTRFS_FEAT_ATTR_PTR(mixed_groups),
315	BTRFS_FEAT_ATTR_PTR(compress_lzo),
316	BTRFS_FEAT_ATTR_PTR(compress_zstd),
317	BTRFS_FEAT_ATTR_PTR(extended_iref),
318	BTRFS_FEAT_ATTR_PTR(raid56),
319	BTRFS_FEAT_ATTR_PTR(skinny_metadata),
320	BTRFS_FEAT_ATTR_PTR(no_holes),
321	BTRFS_FEAT_ATTR_PTR(metadata_uuid),
322	BTRFS_FEAT_ATTR_PTR(free_space_tree),
323	BTRFS_FEAT_ATTR_PTR(raid1c34),
324	BTRFS_FEAT_ATTR_PTR(block_group_tree),
325#ifdef CONFIG_BLK_DEV_ZONED
326	BTRFS_FEAT_ATTR_PTR(zoned),
327#endif
328#ifdef CONFIG_BTRFS_DEBUG
329	BTRFS_FEAT_ATTR_PTR(extent_tree_v2),
330#endif
331#ifdef CONFIG_FS_VERITY
332	BTRFS_FEAT_ATTR_PTR(verity),
333#endif
334	NULL
335};
336
337static const struct attribute_group btrfs_feature_attr_group = {
338	.name = "features",
339	.is_visible = btrfs_feature_visible,
340	.attrs = btrfs_supported_feature_attrs,
341};
342
343static ssize_t rmdir_subvol_show(struct kobject *kobj,
344				 struct kobj_attribute *ka, char *buf)
345{
346	return sysfs_emit(buf, "0\n");
347}
348BTRFS_ATTR(static_feature, rmdir_subvol, rmdir_subvol_show);
349
350static ssize_t supported_checksums_show(struct kobject *kobj,
351					struct kobj_attribute *a, char *buf)
352{
353	ssize_t ret = 0;
354	int i;
355
356	for (i = 0; i < btrfs_get_num_csums(); i++) {
357		/*
358		 * This "trick" only works as long as 'enum btrfs_csum_type' has
359		 * no holes in it
360		 */
361		ret += sysfs_emit_at(buf, ret, "%s%s", (i == 0 ? "" : " "),
362				     btrfs_super_csum_name(i));
363
364	}
365
366	ret += sysfs_emit_at(buf, ret, "\n");
367	return ret;
368}
369BTRFS_ATTR(static_feature, supported_checksums, supported_checksums_show);
370
371static ssize_t send_stream_version_show(struct kobject *kobj,
372					struct kobj_attribute *ka, char *buf)
373{
374	return sysfs_emit(buf, "%d\n", BTRFS_SEND_STREAM_VERSION);
375}
376BTRFS_ATTR(static_feature, send_stream_version, send_stream_version_show);
377
378static const char *rescue_opts[] = {
379	"usebackuproot",
380	"nologreplay",
381	"ignorebadroots",
382	"ignoredatacsums",
383	"all",
384};
385
386static ssize_t supported_rescue_options_show(struct kobject *kobj,
387					     struct kobj_attribute *a,
388					     char *buf)
389{
390	ssize_t ret = 0;
391	int i;
392
393	for (i = 0; i < ARRAY_SIZE(rescue_opts); i++)
394		ret += sysfs_emit_at(buf, ret, "%s%s", (i ? " " : ""), rescue_opts[i]);
395	ret += sysfs_emit_at(buf, ret, "\n");
396	return ret;
397}
398BTRFS_ATTR(static_feature, supported_rescue_options,
399	   supported_rescue_options_show);
400
401static ssize_t supported_sectorsizes_show(struct kobject *kobj,
402					  struct kobj_attribute *a,
403					  char *buf)
404{
405	ssize_t ret = 0;
406
407	/* An artificial limit to only support 4K and PAGE_SIZE */
408	if (PAGE_SIZE > SZ_4K)
409		ret += sysfs_emit_at(buf, ret, "%u ", SZ_4K);
410	ret += sysfs_emit_at(buf, ret, "%lu\n", PAGE_SIZE);
411
412	return ret;
413}
414BTRFS_ATTR(static_feature, supported_sectorsizes,
415	   supported_sectorsizes_show);
416
417static ssize_t acl_show(struct kobject *kobj, struct kobj_attribute *a, char *buf)
418{
419	return sysfs_emit(buf, "%d\n", !!IS_ENABLED(CONFIG_BTRFS_FS_POSIX_ACL));
420}
421BTRFS_ATTR(static_feature, acl, acl_show);
422
423/*
424 * Features which only depend on kernel version.
425 *
426 * These are listed in /sys/fs/btrfs/features along with
427 * btrfs_supported_feature_attrs.
428 */
429static struct attribute *btrfs_supported_static_feature_attrs[] = {
430	BTRFS_ATTR_PTR(static_feature, acl),
431	BTRFS_ATTR_PTR(static_feature, rmdir_subvol),
432	BTRFS_ATTR_PTR(static_feature, supported_checksums),
433	BTRFS_ATTR_PTR(static_feature, send_stream_version),
434	BTRFS_ATTR_PTR(static_feature, supported_rescue_options),
435	BTRFS_ATTR_PTR(static_feature, supported_sectorsizes),
436	NULL
437};
438
439static const struct attribute_group btrfs_static_feature_attr_group = {
440	.name = "features",
441	.attrs = btrfs_supported_static_feature_attrs,
442};
443
444/*
445 * Discard statistics and tunables
446 */
447#define discard_to_fs_info(_kobj)	to_fs_info(get_btrfs_kobj(_kobj))
448
449static ssize_t btrfs_discardable_bytes_show(struct kobject *kobj,
450					    struct kobj_attribute *a,
451					    char *buf)
452{
453	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
454
455	return sysfs_emit(buf, "%lld\n",
456			atomic64_read(&fs_info->discard_ctl.discardable_bytes));
457}
458BTRFS_ATTR(discard, discardable_bytes, btrfs_discardable_bytes_show);
459
460static ssize_t btrfs_discardable_extents_show(struct kobject *kobj,
461					      struct kobj_attribute *a,
462					      char *buf)
463{
464	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
465
466	return sysfs_emit(buf, "%d\n",
467			atomic_read(&fs_info->discard_ctl.discardable_extents));
468}
469BTRFS_ATTR(discard, discardable_extents, btrfs_discardable_extents_show);
470
471static ssize_t btrfs_discard_bitmap_bytes_show(struct kobject *kobj,
472					       struct kobj_attribute *a,
473					       char *buf)
474{
475	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
476
477	return sysfs_emit(buf, "%llu\n",
478			  fs_info->discard_ctl.discard_bitmap_bytes);
479}
480BTRFS_ATTR(discard, discard_bitmap_bytes, btrfs_discard_bitmap_bytes_show);
481
482static ssize_t btrfs_discard_bytes_saved_show(struct kobject *kobj,
483					      struct kobj_attribute *a,
484					      char *buf)
485{
486	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
487
488	return sysfs_emit(buf, "%lld\n",
489		atomic64_read(&fs_info->discard_ctl.discard_bytes_saved));
490}
491BTRFS_ATTR(discard, discard_bytes_saved, btrfs_discard_bytes_saved_show);
492
493static ssize_t btrfs_discard_extent_bytes_show(struct kobject *kobj,
494					       struct kobj_attribute *a,
495					       char *buf)
496{
497	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
498
499	return sysfs_emit(buf, "%llu\n",
500			  fs_info->discard_ctl.discard_extent_bytes);
501}
502BTRFS_ATTR(discard, discard_extent_bytes, btrfs_discard_extent_bytes_show);
503
504static ssize_t btrfs_discard_iops_limit_show(struct kobject *kobj,
505					     struct kobj_attribute *a,
506					     char *buf)
507{
508	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
509
510	return sysfs_emit(buf, "%u\n",
511			  READ_ONCE(fs_info->discard_ctl.iops_limit));
512}
513
514static ssize_t btrfs_discard_iops_limit_store(struct kobject *kobj,
515					      struct kobj_attribute *a,
516					      const char *buf, size_t len)
517{
518	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
519	struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
520	u32 iops_limit;
521	int ret;
522
523	ret = kstrtou32(buf, 10, &iops_limit);
524	if (ret)
525		return -EINVAL;
526
527	WRITE_ONCE(discard_ctl->iops_limit, iops_limit);
528	btrfs_discard_calc_delay(discard_ctl);
529	btrfs_discard_schedule_work(discard_ctl, true);
530	return len;
531}
532BTRFS_ATTR_RW(discard, iops_limit, btrfs_discard_iops_limit_show,
533	      btrfs_discard_iops_limit_store);
534
535static ssize_t btrfs_discard_kbps_limit_show(struct kobject *kobj,
536					     struct kobj_attribute *a,
537					     char *buf)
538{
539	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
540
541	return sysfs_emit(buf, "%u\n",
542			  READ_ONCE(fs_info->discard_ctl.kbps_limit));
543}
544
545static ssize_t btrfs_discard_kbps_limit_store(struct kobject *kobj,
546					      struct kobj_attribute *a,
547					      const char *buf, size_t len)
548{
549	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
550	struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
551	u32 kbps_limit;
552	int ret;
553
554	ret = kstrtou32(buf, 10, &kbps_limit);
555	if (ret)
556		return -EINVAL;
557
558	WRITE_ONCE(discard_ctl->kbps_limit, kbps_limit);
559	btrfs_discard_schedule_work(discard_ctl, true);
560	return len;
561}
562BTRFS_ATTR_RW(discard, kbps_limit, btrfs_discard_kbps_limit_show,
563	      btrfs_discard_kbps_limit_store);
564
565static ssize_t btrfs_discard_max_discard_size_show(struct kobject *kobj,
566						   struct kobj_attribute *a,
567						   char *buf)
568{
569	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
570
571	return sysfs_emit(buf, "%llu\n",
572			  READ_ONCE(fs_info->discard_ctl.max_discard_size));
573}
574
575static ssize_t btrfs_discard_max_discard_size_store(struct kobject *kobj,
576						    struct kobj_attribute *a,
577						    const char *buf, size_t len)
578{
579	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
580	struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
581	u64 max_discard_size;
582	int ret;
583
584	ret = kstrtou64(buf, 10, &max_discard_size);
585	if (ret)
586		return -EINVAL;
587
588	WRITE_ONCE(discard_ctl->max_discard_size, max_discard_size);
589
590	return len;
591}
592BTRFS_ATTR_RW(discard, max_discard_size, btrfs_discard_max_discard_size_show,
593	      btrfs_discard_max_discard_size_store);
594
595/*
596 * Per-filesystem stats for discard (when mounted with discard=async).
597 *
598 * Path: /sys/fs/btrfs/<uuid>/discard/
599 */
600static const struct attribute *discard_attrs[] = {
601	BTRFS_ATTR_PTR(discard, discardable_bytes),
602	BTRFS_ATTR_PTR(discard, discardable_extents),
603	BTRFS_ATTR_PTR(discard, discard_bitmap_bytes),
604	BTRFS_ATTR_PTR(discard, discard_bytes_saved),
605	BTRFS_ATTR_PTR(discard, discard_extent_bytes),
606	BTRFS_ATTR_PTR(discard, iops_limit),
607	BTRFS_ATTR_PTR(discard, kbps_limit),
608	BTRFS_ATTR_PTR(discard, max_discard_size),
609	NULL,
610};
611
612#ifdef CONFIG_BTRFS_DEBUG
613
614/*
615 * Per-filesystem runtime debugging exported via sysfs.
616 *
617 * Path: /sys/fs/btrfs/UUID/debug/
618 */
619static const struct attribute *btrfs_debug_mount_attrs[] = {
620	NULL,
621};
622
623/*
624 * Runtime debugging exported via sysfs, applies to all mounted filesystems.
625 *
626 * Path: /sys/fs/btrfs/debug
627 */
628static struct attribute *btrfs_debug_feature_attrs[] = {
629	NULL
630};
631
632static const struct attribute_group btrfs_debug_feature_attr_group = {
633	.name = "debug",
634	.attrs = btrfs_debug_feature_attrs,
635};
636
637#endif
638
639static ssize_t btrfs_show_u64(u64 *value_ptr, spinlock_t *lock, char *buf)
640{
641	u64 val;
642	if (lock)
643		spin_lock(lock);
644	val = *value_ptr;
645	if (lock)
646		spin_unlock(lock);
647	return sysfs_emit(buf, "%llu\n", val);
648}
649
650static ssize_t global_rsv_size_show(struct kobject *kobj,
651				    struct kobj_attribute *ka, char *buf)
652{
653	struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
654	struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
655	return btrfs_show_u64(&block_rsv->size, &block_rsv->lock, buf);
656}
657BTRFS_ATTR(allocation, global_rsv_size, global_rsv_size_show);
658
659static ssize_t global_rsv_reserved_show(struct kobject *kobj,
660					struct kobj_attribute *a, char *buf)
661{
662	struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
663	struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
664	return btrfs_show_u64(&block_rsv->reserved, &block_rsv->lock, buf);
665}
666BTRFS_ATTR(allocation, global_rsv_reserved, global_rsv_reserved_show);
667
668#define to_space_info(_kobj) container_of(_kobj, struct btrfs_space_info, kobj)
669#define to_raid_kobj(_kobj) container_of(_kobj, struct raid_kobject, kobj)
670
671static ssize_t raid_bytes_show(struct kobject *kobj,
672			       struct kobj_attribute *attr, char *buf);
673BTRFS_ATTR(raid, total_bytes, raid_bytes_show);
674BTRFS_ATTR(raid, used_bytes, raid_bytes_show);
675
676static ssize_t raid_bytes_show(struct kobject *kobj,
677			       struct kobj_attribute *attr, char *buf)
678
679{
680	struct btrfs_space_info *sinfo = to_space_info(kobj->parent);
681	struct btrfs_block_group *block_group;
682	int index = btrfs_bg_flags_to_raid_index(to_raid_kobj(kobj)->flags);
683	u64 val = 0;
684
685	down_read(&sinfo->groups_sem);
686	list_for_each_entry(block_group, &sinfo->block_groups[index], list) {
687		if (&attr->attr == BTRFS_ATTR_PTR(raid, total_bytes))
688			val += block_group->length;
689		else
690			val += block_group->used;
691	}
692	up_read(&sinfo->groups_sem);
693	return sysfs_emit(buf, "%llu\n", val);
694}
695
696/*
697 * Allocation information about block group profiles.
698 *
699 * Path: /sys/fs/btrfs/<uuid>/allocation/<bg-type>/<bg-profile>/
700 */
701static struct attribute *raid_attrs[] = {
702	BTRFS_ATTR_PTR(raid, total_bytes),
703	BTRFS_ATTR_PTR(raid, used_bytes),
704	NULL
705};
706ATTRIBUTE_GROUPS(raid);
707
708static void release_raid_kobj(struct kobject *kobj)
709{
710	kfree(to_raid_kobj(kobj));
711}
712
713static const struct kobj_type btrfs_raid_ktype = {
714	.sysfs_ops = &kobj_sysfs_ops,
715	.release = release_raid_kobj,
716	.default_groups = raid_groups,
717};
718
719#define SPACE_INFO_ATTR(field)						\
720static ssize_t btrfs_space_info_show_##field(struct kobject *kobj,	\
721					     struct kobj_attribute *a,	\
722					     char *buf)			\
723{									\
724	struct btrfs_space_info *sinfo = to_space_info(kobj);		\
725	return btrfs_show_u64(&sinfo->field, &sinfo->lock, buf);	\
726}									\
727BTRFS_ATTR(space_info, field, btrfs_space_info_show_##field)
728
729static ssize_t btrfs_chunk_size_show(struct kobject *kobj,
730				     struct kobj_attribute *a, char *buf)
731{
732	struct btrfs_space_info *sinfo = to_space_info(kobj);
733
734	return sysfs_emit(buf, "%llu\n", READ_ONCE(sinfo->chunk_size));
735}
736
737/*
738 * Store new chunk size in space info. Can be called on a read-only filesystem.
739 *
740 * If the new chunk size value is larger than 10% of free space it is reduced
741 * to match that limit. Alignment must be to 256M and the system chunk size
742 * cannot be set.
743 */
744static ssize_t btrfs_chunk_size_store(struct kobject *kobj,
745				      struct kobj_attribute *a,
746				      const char *buf, size_t len)
747{
748	struct btrfs_space_info *space_info = to_space_info(kobj);
749	struct btrfs_fs_info *fs_info = to_fs_info(get_btrfs_kobj(kobj));
750	char *retptr;
751	u64 val;
752
753	if (!capable(CAP_SYS_ADMIN))
754		return -EPERM;
755
756	if (!fs_info->fs_devices)
757		return -EINVAL;
758
759	if (btrfs_is_zoned(fs_info))
760		return -EINVAL;
761
762	/* System block type must not be changed. */
763	if (space_info->flags & BTRFS_BLOCK_GROUP_SYSTEM)
764		return -EPERM;
765
766	val = memparse(buf, &retptr);
767	/* There could be trailing '\n', also catch any typos after the value */
768	retptr = skip_spaces(retptr);
769	if (*retptr != 0 || val == 0)
770		return -EINVAL;
771
772	val = min(val, BTRFS_MAX_DATA_CHUNK_SIZE);
773
774	/* Limit stripe size to 10% of available space. */
775	val = min(mult_perc(fs_info->fs_devices->total_rw_bytes, 10), val);
776
777	/* Must be multiple of 256M. */
778	val &= ~((u64)SZ_256M - 1);
779
780	/* Must be at least 256M. */
781	if (val < SZ_256M)
782		return -EINVAL;
783
784	btrfs_update_space_info_chunk_size(space_info, val);
785
786	return len;
787}
788
789static ssize_t btrfs_size_classes_show(struct kobject *kobj,
790				       struct kobj_attribute *a, char *buf)
791{
792	struct btrfs_space_info *sinfo = to_space_info(kobj);
793	struct btrfs_block_group *bg;
794	u32 none = 0;
795	u32 small = 0;
796	u32 medium = 0;
797	u32 large = 0;
798
799	for (int i = 0; i < BTRFS_NR_RAID_TYPES; ++i) {
800		down_read(&sinfo->groups_sem);
801		list_for_each_entry(bg, &sinfo->block_groups[i], list) {
802			if (!btrfs_block_group_should_use_size_class(bg))
803				continue;
804			switch (bg->size_class) {
805			case BTRFS_BG_SZ_NONE:
806				none++;
807				break;
808			case BTRFS_BG_SZ_SMALL:
809				small++;
810				break;
811			case BTRFS_BG_SZ_MEDIUM:
812				medium++;
813				break;
814			case BTRFS_BG_SZ_LARGE:
815				large++;
816				break;
817			}
818		}
819		up_read(&sinfo->groups_sem);
820	}
821	return sysfs_emit(buf, "none %u\n"
822			       "small %u\n"
823			       "medium %u\n"
824			       "large %u\n",
825			       none, small, medium, large);
826}
827
828#ifdef CONFIG_BTRFS_DEBUG
829/*
830 * Request chunk allocation with current chunk size.
831 */
832static ssize_t btrfs_force_chunk_alloc_store(struct kobject *kobj,
833					     struct kobj_attribute *a,
834					     const char *buf, size_t len)
835{
836	struct btrfs_space_info *space_info = to_space_info(kobj);
837	struct btrfs_fs_info *fs_info = to_fs_info(get_btrfs_kobj(kobj));
838	struct btrfs_trans_handle *trans;
839	bool val;
840	int ret;
841
842	if (!capable(CAP_SYS_ADMIN))
843		return -EPERM;
844
845	if (sb_rdonly(fs_info->sb))
846		return -EROFS;
847
848	ret = kstrtobool(buf, &val);
849	if (ret)
850		return ret;
851
852	if (!val)
853		return -EINVAL;
854
855	/*
856	 * This is unsafe to be called from sysfs context and may cause
857	 * unexpected problems.
858	 */
859	trans = btrfs_start_transaction(fs_info->tree_root, 0);
860	if (IS_ERR(trans))
861		return PTR_ERR(trans);
862	ret = btrfs_force_chunk_alloc(trans, space_info->flags);
863	btrfs_end_transaction(trans);
864
865	if (ret == 1)
866		return len;
867
868	return -ENOSPC;
869}
870BTRFS_ATTR_W(space_info, force_chunk_alloc, btrfs_force_chunk_alloc_store);
871
872#endif
873
874SPACE_INFO_ATTR(flags);
875SPACE_INFO_ATTR(total_bytes);
876SPACE_INFO_ATTR(bytes_used);
877SPACE_INFO_ATTR(bytes_pinned);
878SPACE_INFO_ATTR(bytes_reserved);
879SPACE_INFO_ATTR(bytes_may_use);
880SPACE_INFO_ATTR(bytes_readonly);
881SPACE_INFO_ATTR(bytes_zone_unusable);
882SPACE_INFO_ATTR(disk_used);
883SPACE_INFO_ATTR(disk_total);
884BTRFS_ATTR_RW(space_info, chunk_size, btrfs_chunk_size_show, btrfs_chunk_size_store);
885BTRFS_ATTR(space_info, size_classes, btrfs_size_classes_show);
886
887static ssize_t btrfs_sinfo_bg_reclaim_threshold_show(struct kobject *kobj,
888						     struct kobj_attribute *a,
889						     char *buf)
890{
891	struct btrfs_space_info *space_info = to_space_info(kobj);
892
893	return sysfs_emit(buf, "%d\n", READ_ONCE(space_info->bg_reclaim_threshold));
894}
895
896static ssize_t btrfs_sinfo_bg_reclaim_threshold_store(struct kobject *kobj,
897						      struct kobj_attribute *a,
898						      const char *buf, size_t len)
899{
900	struct btrfs_space_info *space_info = to_space_info(kobj);
901	int thresh;
902	int ret;
903
904	ret = kstrtoint(buf, 10, &thresh);
905	if (ret)
906		return ret;
907
908	if (thresh < 0 || thresh > 100)
909		return -EINVAL;
910
911	WRITE_ONCE(space_info->bg_reclaim_threshold, thresh);
912
913	return len;
914}
915
916BTRFS_ATTR_RW(space_info, bg_reclaim_threshold,
917	      btrfs_sinfo_bg_reclaim_threshold_show,
918	      btrfs_sinfo_bg_reclaim_threshold_store);
919
920/*
921 * Allocation information about block group types.
922 *
923 * Path: /sys/fs/btrfs/<uuid>/allocation/<bg-type>/
924 */
925static struct attribute *space_info_attrs[] = {
926	BTRFS_ATTR_PTR(space_info, flags),
927	BTRFS_ATTR_PTR(space_info, total_bytes),
928	BTRFS_ATTR_PTR(space_info, bytes_used),
929	BTRFS_ATTR_PTR(space_info, bytes_pinned),
930	BTRFS_ATTR_PTR(space_info, bytes_reserved),
931	BTRFS_ATTR_PTR(space_info, bytes_may_use),
932	BTRFS_ATTR_PTR(space_info, bytes_readonly),
933	BTRFS_ATTR_PTR(space_info, bytes_zone_unusable),
934	BTRFS_ATTR_PTR(space_info, disk_used),
935	BTRFS_ATTR_PTR(space_info, disk_total),
936	BTRFS_ATTR_PTR(space_info, bg_reclaim_threshold),
937	BTRFS_ATTR_PTR(space_info, chunk_size),
938	BTRFS_ATTR_PTR(space_info, size_classes),
939#ifdef CONFIG_BTRFS_DEBUG
940	BTRFS_ATTR_PTR(space_info, force_chunk_alloc),
941#endif
942	NULL,
943};
944ATTRIBUTE_GROUPS(space_info);
945
946static void space_info_release(struct kobject *kobj)
947{
948	struct btrfs_space_info *sinfo = to_space_info(kobj);
949	kfree(sinfo);
950}
951
952static const struct kobj_type space_info_ktype = {
953	.sysfs_ops = &kobj_sysfs_ops,
954	.release = space_info_release,
955	.default_groups = space_info_groups,
956};
957
958/*
959 * Allocation information about block groups.
960 *
961 * Path: /sys/fs/btrfs/<uuid>/allocation/
962 */
963static const struct attribute *allocation_attrs[] = {
964	BTRFS_ATTR_PTR(allocation, global_rsv_reserved),
965	BTRFS_ATTR_PTR(allocation, global_rsv_size),
966	NULL,
967};
968
969static ssize_t btrfs_label_show(struct kobject *kobj,
970				struct kobj_attribute *a, char *buf)
971{
972	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
973	char *label = fs_info->super_copy->label;
974	ssize_t ret;
975
976	spin_lock(&fs_info->super_lock);
977	ret = sysfs_emit(buf, label[0] ? "%s\n" : "%s", label);
978	spin_unlock(&fs_info->super_lock);
979
980	return ret;
981}
982
983static ssize_t btrfs_label_store(struct kobject *kobj,
984				 struct kobj_attribute *a,
985				 const char *buf, size_t len)
986{
987	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
988	size_t p_len;
989
990	if (!fs_info)
991		return -EPERM;
992
993	if (sb_rdonly(fs_info->sb))
994		return -EROFS;
995
996	/*
997	 * p_len is the len until the first occurrence of either
998	 * '\n' or '\0'
999	 */
1000	p_len = strcspn(buf, "\n");
1001
1002	if (p_len >= BTRFS_LABEL_SIZE)
1003		return -EINVAL;
1004
1005	spin_lock(&fs_info->super_lock);
1006	memset(fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE);
1007	memcpy(fs_info->super_copy->label, buf, p_len);
1008	spin_unlock(&fs_info->super_lock);
1009
1010	/*
1011	 * We don't want to do full transaction commit from inside sysfs
1012	 */
1013	set_bit(BTRFS_FS_NEED_TRANS_COMMIT, &fs_info->flags);
1014	wake_up_process(fs_info->transaction_kthread);
1015
1016	return len;
1017}
1018BTRFS_ATTR_RW(, label, btrfs_label_show, btrfs_label_store);
1019
1020static ssize_t btrfs_nodesize_show(struct kobject *kobj,
1021				struct kobj_attribute *a, char *buf)
1022{
1023	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1024
1025	return sysfs_emit(buf, "%u\n", fs_info->super_copy->nodesize);
1026}
1027
1028BTRFS_ATTR(, nodesize, btrfs_nodesize_show);
1029
1030static ssize_t btrfs_sectorsize_show(struct kobject *kobj,
1031				struct kobj_attribute *a, char *buf)
1032{
1033	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1034
1035	return sysfs_emit(buf, "%u\n", fs_info->super_copy->sectorsize);
1036}
1037
1038BTRFS_ATTR(, sectorsize, btrfs_sectorsize_show);
1039
1040static ssize_t btrfs_commit_stats_show(struct kobject *kobj,
1041				       struct kobj_attribute *a, char *buf)
1042{
1043	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1044
1045	return sysfs_emit(buf,
1046		"commits %llu\n"
1047		"last_commit_ms %llu\n"
1048		"max_commit_ms %llu\n"
1049		"total_commit_ms %llu\n",
1050		fs_info->commit_stats.commit_count,
1051		div_u64(fs_info->commit_stats.last_commit_dur, NSEC_PER_MSEC),
1052		div_u64(fs_info->commit_stats.max_commit_dur, NSEC_PER_MSEC),
1053		div_u64(fs_info->commit_stats.total_commit_dur, NSEC_PER_MSEC));
1054}
1055
1056static ssize_t btrfs_commit_stats_store(struct kobject *kobj,
1057					struct kobj_attribute *a,
1058					const char *buf, size_t len)
1059{
1060	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1061	unsigned long val;
1062	int ret;
1063
1064	if (!fs_info)
1065		return -EPERM;
1066
1067	if (!capable(CAP_SYS_RESOURCE))
1068		return -EPERM;
1069
1070	ret = kstrtoul(buf, 10, &val);
1071	if (ret)
1072		return ret;
1073	if (val)
1074		return -EINVAL;
1075
1076	WRITE_ONCE(fs_info->commit_stats.max_commit_dur, 0);
1077
1078	return len;
1079}
1080BTRFS_ATTR_RW(, commit_stats, btrfs_commit_stats_show, btrfs_commit_stats_store);
1081
1082static ssize_t btrfs_clone_alignment_show(struct kobject *kobj,
1083				struct kobj_attribute *a, char *buf)
1084{
1085	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1086
1087	return sysfs_emit(buf, "%u\n", fs_info->super_copy->sectorsize);
1088}
1089
1090BTRFS_ATTR(, clone_alignment, btrfs_clone_alignment_show);
1091
1092static ssize_t quota_override_show(struct kobject *kobj,
1093				   struct kobj_attribute *a, char *buf)
1094{
1095	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1096	int quota_override;
1097
1098	quota_override = test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
1099	return sysfs_emit(buf, "%d\n", quota_override);
1100}
1101
1102static ssize_t quota_override_store(struct kobject *kobj,
1103				    struct kobj_attribute *a,
1104				    const char *buf, size_t len)
1105{
1106	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1107	unsigned long knob;
1108	int err;
1109
1110	if (!fs_info)
1111		return -EPERM;
1112
1113	if (!capable(CAP_SYS_RESOURCE))
1114		return -EPERM;
1115
1116	err = kstrtoul(buf, 10, &knob);
1117	if (err)
1118		return err;
1119	if (knob > 1)
1120		return -EINVAL;
1121
1122	if (knob)
1123		set_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
1124	else
1125		clear_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
1126
1127	return len;
1128}
1129
1130BTRFS_ATTR_RW(, quota_override, quota_override_show, quota_override_store);
1131
1132static ssize_t btrfs_metadata_uuid_show(struct kobject *kobj,
1133				struct kobj_attribute *a, char *buf)
1134{
1135	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1136
1137	return sysfs_emit(buf, "%pU\n", fs_info->fs_devices->metadata_uuid);
1138}
1139
1140BTRFS_ATTR(, metadata_uuid, btrfs_metadata_uuid_show);
1141
1142static ssize_t btrfs_checksum_show(struct kobject *kobj,
1143				   struct kobj_attribute *a, char *buf)
1144{
1145	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1146	u16 csum_type = btrfs_super_csum_type(fs_info->super_copy);
1147
1148	return sysfs_emit(buf, "%s (%s)\n",
1149			  btrfs_super_csum_name(csum_type),
1150			  crypto_shash_driver_name(fs_info->csum_shash));
1151}
1152
1153BTRFS_ATTR(, checksum, btrfs_checksum_show);
1154
1155static ssize_t btrfs_exclusive_operation_show(struct kobject *kobj,
1156		struct kobj_attribute *a, char *buf)
1157{
1158	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1159	const char *str;
1160
1161	switch (READ_ONCE(fs_info->exclusive_operation)) {
1162		case  BTRFS_EXCLOP_NONE:
1163			str = "none\n";
1164			break;
1165		case BTRFS_EXCLOP_BALANCE:
1166			str = "balance\n";
1167			break;
1168		case BTRFS_EXCLOP_BALANCE_PAUSED:
1169			str = "balance paused\n";
1170			break;
1171		case BTRFS_EXCLOP_DEV_ADD:
1172			str = "device add\n";
1173			break;
1174		case BTRFS_EXCLOP_DEV_REMOVE:
1175			str = "device remove\n";
1176			break;
1177		case BTRFS_EXCLOP_DEV_REPLACE:
1178			str = "device replace\n";
1179			break;
1180		case BTRFS_EXCLOP_RESIZE:
1181			str = "resize\n";
1182			break;
1183		case BTRFS_EXCLOP_SWAP_ACTIVATE:
1184			str = "swap activate\n";
1185			break;
1186		default:
1187			str = "UNKNOWN\n";
1188			break;
1189	}
1190	return sysfs_emit(buf, "%s", str);
1191}
1192BTRFS_ATTR(, exclusive_operation, btrfs_exclusive_operation_show);
1193
1194static ssize_t btrfs_generation_show(struct kobject *kobj,
1195				     struct kobj_attribute *a, char *buf)
1196{
1197	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1198
1199	return sysfs_emit(buf, "%llu\n", fs_info->generation);
1200}
1201BTRFS_ATTR(, generation, btrfs_generation_show);
1202
1203static const char * const btrfs_read_policy_name[] = { "pid" };
1204
1205static ssize_t btrfs_read_policy_show(struct kobject *kobj,
1206				      struct kobj_attribute *a, char *buf)
1207{
1208	struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
1209	ssize_t ret = 0;
1210	int i;
1211
1212	for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
1213		if (fs_devices->read_policy == i)
1214			ret += sysfs_emit_at(buf, ret, "%s[%s]",
1215					 (ret == 0 ? "" : " "),
1216					 btrfs_read_policy_name[i]);
1217		else
1218			ret += sysfs_emit_at(buf, ret, "%s%s",
1219					 (ret == 0 ? "" : " "),
1220					 btrfs_read_policy_name[i]);
1221	}
1222
1223	ret += sysfs_emit_at(buf, ret, "\n");
1224
1225	return ret;
1226}
1227
1228static ssize_t btrfs_read_policy_store(struct kobject *kobj,
1229				       struct kobj_attribute *a,
1230				       const char *buf, size_t len)
1231{
1232	struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
1233	int i;
1234
1235	for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
1236		if (sysfs_streq(buf, btrfs_read_policy_name[i])) {
1237			if (i != fs_devices->read_policy) {
1238				fs_devices->read_policy = i;
1239				btrfs_info(fs_devices->fs_info,
1240					   "read policy set to '%s'",
1241					   btrfs_read_policy_name[i]);
1242			}
1243			return len;
1244		}
1245	}
1246
1247	return -EINVAL;
1248}
1249BTRFS_ATTR_RW(, read_policy, btrfs_read_policy_show, btrfs_read_policy_store);
1250
1251static ssize_t btrfs_bg_reclaim_threshold_show(struct kobject *kobj,
1252					       struct kobj_attribute *a,
1253					       char *buf)
1254{
1255	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1256
1257	return sysfs_emit(buf, "%d\n", READ_ONCE(fs_info->bg_reclaim_threshold));
1258}
1259
1260static ssize_t btrfs_bg_reclaim_threshold_store(struct kobject *kobj,
1261						struct kobj_attribute *a,
1262						const char *buf, size_t len)
1263{
1264	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1265	int thresh;
1266	int ret;
1267
1268	ret = kstrtoint(buf, 10, &thresh);
1269	if (ret)
1270		return ret;
1271
1272#ifdef CONFIG_BTRFS_DEBUG
1273	if (thresh != 0 && (thresh > 100))
1274		return -EINVAL;
1275#else
1276	if (thresh != 0 && (thresh <= 50 || thresh > 100))
1277		return -EINVAL;
1278#endif
1279
1280	WRITE_ONCE(fs_info->bg_reclaim_threshold, thresh);
1281
1282	return len;
1283}
1284BTRFS_ATTR_RW(, bg_reclaim_threshold, btrfs_bg_reclaim_threshold_show,
1285	      btrfs_bg_reclaim_threshold_store);
1286
1287/*
1288 * Per-filesystem information and stats.
1289 *
1290 * Path: /sys/fs/btrfs/<uuid>/
1291 */
1292static const struct attribute *btrfs_attrs[] = {
1293	BTRFS_ATTR_PTR(, label),
1294	BTRFS_ATTR_PTR(, nodesize),
1295	BTRFS_ATTR_PTR(, sectorsize),
1296	BTRFS_ATTR_PTR(, clone_alignment),
1297	BTRFS_ATTR_PTR(, quota_override),
1298	BTRFS_ATTR_PTR(, metadata_uuid),
1299	BTRFS_ATTR_PTR(, checksum),
1300	BTRFS_ATTR_PTR(, exclusive_operation),
1301	BTRFS_ATTR_PTR(, generation),
1302	BTRFS_ATTR_PTR(, read_policy),
1303	BTRFS_ATTR_PTR(, bg_reclaim_threshold),
1304	BTRFS_ATTR_PTR(, commit_stats),
1305	NULL,
1306};
1307
1308static void btrfs_release_fsid_kobj(struct kobject *kobj)
1309{
1310	struct btrfs_fs_devices *fs_devs = to_fs_devs(kobj);
1311
1312	memset(&fs_devs->fsid_kobj, 0, sizeof(struct kobject));
1313	complete(&fs_devs->kobj_unregister);
1314}
1315
1316static const struct kobj_type btrfs_ktype = {
1317	.sysfs_ops	= &kobj_sysfs_ops,
1318	.release	= btrfs_release_fsid_kobj,
1319};
1320
1321static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj)
1322{
1323	if (kobj->ktype != &btrfs_ktype)
1324		return NULL;
1325	return container_of(kobj, struct btrfs_fs_devices, fsid_kobj);
1326}
1327
1328static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)
1329{
1330	if (kobj->ktype != &btrfs_ktype)
1331		return NULL;
1332	return to_fs_devs(kobj)->fs_info;
1333}
1334
1335static struct kobject *get_btrfs_kobj(struct kobject *kobj)
1336{
1337	while (kobj) {
1338		if (kobj->ktype == &btrfs_ktype)
1339			return kobj;
1340		kobj = kobj->parent;
1341	}
1342	return NULL;
1343}
1344
1345#define NUM_FEATURE_BITS 64
1346#define BTRFS_FEATURE_NAME_MAX 13
1347static char btrfs_unknown_feature_names[FEAT_MAX][NUM_FEATURE_BITS][BTRFS_FEATURE_NAME_MAX];
1348static struct btrfs_feature_attr btrfs_feature_attrs[FEAT_MAX][NUM_FEATURE_BITS];
1349
1350static_assert(ARRAY_SIZE(btrfs_unknown_feature_names) ==
1351	      ARRAY_SIZE(btrfs_feature_attrs));
1352static_assert(ARRAY_SIZE(btrfs_unknown_feature_names[0]) ==
1353	      ARRAY_SIZE(btrfs_feature_attrs[0]));
1354
1355static const u64 supported_feature_masks[FEAT_MAX] = {
1356	[FEAT_COMPAT]    = BTRFS_FEATURE_COMPAT_SUPP,
1357	[FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP,
1358	[FEAT_INCOMPAT]  = BTRFS_FEATURE_INCOMPAT_SUPP,
1359};
1360
1361static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add)
1362{
1363	int set;
1364
1365	for (set = 0; set < FEAT_MAX; set++) {
1366		int i;
1367		struct attribute *attrs[2];
1368		struct attribute_group agroup = {
1369			.name = "features",
1370			.attrs = attrs,
1371		};
1372		u64 features = get_features(fs_info, set);
1373		features &= ~supported_feature_masks[set];
1374
1375		if (!features)
1376			continue;
1377
1378		attrs[1] = NULL;
1379		for (i = 0; i < NUM_FEATURE_BITS; i++) {
1380			struct btrfs_feature_attr *fa;
1381
1382			if (!(features & (1ULL << i)))
1383				continue;
1384
1385			fa = &btrfs_feature_attrs[set][i];
1386			attrs[0] = &fa->kobj_attr.attr;
1387			if (add) {
1388				int ret;
1389				ret = sysfs_merge_group(&fs_info->fs_devices->fsid_kobj,
1390							&agroup);
1391				if (ret)
1392					return ret;
1393			} else
1394				sysfs_unmerge_group(&fs_info->fs_devices->fsid_kobj,
1395						    &agroup);
1396		}
1397
1398	}
1399	return 0;
1400}
1401
1402static void __btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1403{
1404	if (fs_devs->devinfo_kobj) {
1405		kobject_del(fs_devs->devinfo_kobj);
1406		kobject_put(fs_devs->devinfo_kobj);
1407		fs_devs->devinfo_kobj = NULL;
1408	}
1409
1410	if (fs_devs->devices_kobj) {
1411		kobject_del(fs_devs->devices_kobj);
1412		kobject_put(fs_devs->devices_kobj);
1413		fs_devs->devices_kobj = NULL;
1414	}
1415
1416	if (fs_devs->fsid_kobj.state_initialized) {
1417		kobject_del(&fs_devs->fsid_kobj);
1418		kobject_put(&fs_devs->fsid_kobj);
1419		wait_for_completion(&fs_devs->kobj_unregister);
1420	}
1421}
1422
1423/* when fs_devs is NULL it will remove all fsid kobject */
1424void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1425{
1426	struct list_head *fs_uuids = btrfs_get_fs_uuids();
1427
1428	if (fs_devs) {
1429		__btrfs_sysfs_remove_fsid(fs_devs);
1430		return;
1431	}
1432
1433	list_for_each_entry(fs_devs, fs_uuids, fs_list) {
1434		__btrfs_sysfs_remove_fsid(fs_devs);
1435	}
1436}
1437
1438static void btrfs_sysfs_remove_fs_devices(struct btrfs_fs_devices *fs_devices)
1439{
1440	struct btrfs_device *device;
1441	struct btrfs_fs_devices *seed;
1442
1443	list_for_each_entry(device, &fs_devices->devices, dev_list)
1444		btrfs_sysfs_remove_device(device);
1445
1446	list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
1447		list_for_each_entry(device, &seed->devices, dev_list)
1448			btrfs_sysfs_remove_device(device);
1449	}
1450}
1451
1452void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info)
1453{
1454	struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
1455
1456	sysfs_remove_link(fsid_kobj, "bdi");
1457
1458	if (fs_info->space_info_kobj) {
1459		sysfs_remove_files(fs_info->space_info_kobj, allocation_attrs);
1460		kobject_del(fs_info->space_info_kobj);
1461		kobject_put(fs_info->space_info_kobj);
1462	}
1463	if (fs_info->discard_kobj) {
1464		sysfs_remove_files(fs_info->discard_kobj, discard_attrs);
1465		kobject_del(fs_info->discard_kobj);
1466		kobject_put(fs_info->discard_kobj);
1467	}
1468#ifdef CONFIG_BTRFS_DEBUG
1469	if (fs_info->debug_kobj) {
1470		sysfs_remove_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
1471		kobject_del(fs_info->debug_kobj);
1472		kobject_put(fs_info->debug_kobj);
1473	}
1474#endif
1475	addrm_unknown_feature_attrs(fs_info, false);
1476	sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
1477	sysfs_remove_files(fsid_kobj, btrfs_attrs);
1478	btrfs_sysfs_remove_fs_devices(fs_info->fs_devices);
1479}
1480
1481static const char * const btrfs_feature_set_names[FEAT_MAX] = {
1482	[FEAT_COMPAT]	 = "compat",
1483	[FEAT_COMPAT_RO] = "compat_ro",
1484	[FEAT_INCOMPAT]	 = "incompat",
1485};
1486
1487const char *btrfs_feature_set_name(enum btrfs_feature_set set)
1488{
1489	return btrfs_feature_set_names[set];
1490}
1491
1492char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags)
1493{
1494	size_t bufsize = 4096; /* safe max, 64 names * 64 bytes */
1495	int len = 0;
1496	int i;
1497	char *str;
1498
1499	str = kmalloc(bufsize, GFP_KERNEL);
1500	if (!str)
1501		return str;
1502
1503	for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1504		const char *name;
1505
1506		if (!(flags & (1ULL << i)))
1507			continue;
1508
1509		name = btrfs_feature_attrs[set][i].kobj_attr.attr.name;
1510		len += scnprintf(str + len, bufsize - len, "%s%s",
1511				len ? "," : "", name);
1512	}
1513
1514	return str;
1515}
1516
1517static void init_feature_attrs(void)
1518{
1519	struct btrfs_feature_attr *fa;
1520	int set, i;
1521
1522	memset(btrfs_feature_attrs, 0, sizeof(btrfs_feature_attrs));
1523	memset(btrfs_unknown_feature_names, 0,
1524	       sizeof(btrfs_unknown_feature_names));
1525
1526	for (i = 0; btrfs_supported_feature_attrs[i]; i++) {
1527		struct btrfs_feature_attr *sfa;
1528		struct attribute *a = btrfs_supported_feature_attrs[i];
1529		int bit;
1530		sfa = attr_to_btrfs_feature_attr(a);
1531		bit = ilog2(sfa->feature_bit);
1532		fa = &btrfs_feature_attrs[sfa->feature_set][bit];
1533
1534		fa->kobj_attr.attr.name = sfa->kobj_attr.attr.name;
1535	}
1536
1537	for (set = 0; set < FEAT_MAX; set++) {
1538		for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1539			char *name = btrfs_unknown_feature_names[set][i];
1540			fa = &btrfs_feature_attrs[set][i];
1541
1542			if (fa->kobj_attr.attr.name)
1543				continue;
1544
1545			snprintf(name, BTRFS_FEATURE_NAME_MAX, "%s:%u",
1546				 btrfs_feature_set_names[set], i);
1547
1548			fa->kobj_attr.attr.name = name;
1549			fa->kobj_attr.attr.mode = S_IRUGO;
1550			fa->feature_set = set;
1551			fa->feature_bit = 1ULL << i;
1552		}
1553	}
1554}
1555
1556/*
1557 * Create a sysfs entry for a given block group type at path
1558 * /sys/fs/btrfs/UUID/allocation/data/TYPE
1559 */
1560void btrfs_sysfs_add_block_group_type(struct btrfs_block_group *cache)
1561{
1562	struct btrfs_fs_info *fs_info = cache->fs_info;
1563	struct btrfs_space_info *space_info = cache->space_info;
1564	struct raid_kobject *rkobj;
1565	const int index = btrfs_bg_flags_to_raid_index(cache->flags);
1566	unsigned int nofs_flag;
1567	int ret;
1568
1569	/*
1570	 * Setup a NOFS context because kobject_add(), deep in its call chain,
1571	 * does GFP_KERNEL allocations, and we are often called in a context
1572	 * where if reclaim is triggered we can deadlock (we are either holding
1573	 * a transaction handle or some lock required for a transaction
1574	 * commit).
1575	 */
1576	nofs_flag = memalloc_nofs_save();
1577
1578	rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS);
1579	if (!rkobj) {
1580		memalloc_nofs_restore(nofs_flag);
1581		btrfs_warn(cache->fs_info,
1582				"couldn't alloc memory for raid level kobject");
1583		return;
1584	}
1585
1586	rkobj->flags = cache->flags;
1587	kobject_init(&rkobj->kobj, &btrfs_raid_ktype);
1588
1589	/*
1590	 * We call this either on mount, or if we've created a block group for a
1591	 * new index type while running (i.e. when restriping).  The running
1592	 * case is tricky because we could race with other threads, so we need
1593	 * to have this check to make sure we didn't already init the kobject.
1594	 *
1595	 * We don't have to protect on the free side because it only happens on
1596	 * unmount.
1597	 */
1598	spin_lock(&space_info->lock);
1599	if (space_info->block_group_kobjs[index]) {
1600		spin_unlock(&space_info->lock);
1601		kobject_put(&rkobj->kobj);
1602		return;
1603	} else {
1604		space_info->block_group_kobjs[index] = &rkobj->kobj;
1605	}
1606	spin_unlock(&space_info->lock);
1607
1608	ret = kobject_add(&rkobj->kobj, &space_info->kobj, "%s",
1609			  btrfs_bg_type_to_raid_name(rkobj->flags));
1610	memalloc_nofs_restore(nofs_flag);
1611	if (ret) {
1612		spin_lock(&space_info->lock);
1613		space_info->block_group_kobjs[index] = NULL;
1614		spin_unlock(&space_info->lock);
1615		kobject_put(&rkobj->kobj);
1616		btrfs_warn(fs_info,
1617			"failed to add kobject for block cache, ignoring");
1618		return;
1619	}
1620}
1621
1622/*
1623 * Remove sysfs directories for all block group types of a given space info and
1624 * the space info as well
1625 */
1626void btrfs_sysfs_remove_space_info(struct btrfs_space_info *space_info)
1627{
1628	int i;
1629
1630	for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
1631		struct kobject *kobj;
1632
1633		kobj = space_info->block_group_kobjs[i];
1634		space_info->block_group_kobjs[i] = NULL;
1635		if (kobj) {
1636			kobject_del(kobj);
1637			kobject_put(kobj);
1638		}
1639	}
1640	kobject_del(&space_info->kobj);
1641	kobject_put(&space_info->kobj);
1642}
1643
1644static const char *alloc_name(u64 flags)
1645{
1646	switch (flags) {
1647	case BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA:
1648		return "mixed";
1649	case BTRFS_BLOCK_GROUP_METADATA:
1650		return "metadata";
1651	case BTRFS_BLOCK_GROUP_DATA:
1652		return "data";
1653	case BTRFS_BLOCK_GROUP_SYSTEM:
1654		return "system";
1655	default:
1656		WARN_ON(1);
1657		return "invalid-combination";
1658	}
1659}
1660
1661/*
1662 * Create a sysfs entry for a space info type at path
1663 * /sys/fs/btrfs/UUID/allocation/TYPE
1664 */
1665int btrfs_sysfs_add_space_info_type(struct btrfs_fs_info *fs_info,
1666				    struct btrfs_space_info *space_info)
1667{
1668	int ret;
1669
1670	ret = kobject_init_and_add(&space_info->kobj, &space_info_ktype,
1671				   fs_info->space_info_kobj, "%s",
1672				   alloc_name(space_info->flags));
1673	if (ret) {
1674		kobject_put(&space_info->kobj);
1675		return ret;
1676	}
1677
1678	return 0;
1679}
1680
1681void btrfs_sysfs_remove_device(struct btrfs_device *device)
1682{
1683	struct kobject *devices_kobj;
1684
1685	/*
1686	 * Seed fs_devices devices_kobj aren't used, fetch kobject from the
1687	 * fs_info::fs_devices.
1688	 */
1689	devices_kobj = device->fs_info->fs_devices->devices_kobj;
1690	ASSERT(devices_kobj);
1691
1692	if (device->bdev)
1693		sysfs_remove_link(devices_kobj, bdev_kobj(device->bdev)->name);
1694
1695	if (device->devid_kobj.state_initialized) {
1696		kobject_del(&device->devid_kobj);
1697		kobject_put(&device->devid_kobj);
1698		wait_for_completion(&device->kobj_unregister);
1699	}
1700}
1701
1702static ssize_t btrfs_devinfo_in_fs_metadata_show(struct kobject *kobj,
1703					         struct kobj_attribute *a,
1704					         char *buf)
1705{
1706	int val;
1707	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1708						   devid_kobj);
1709
1710	val = !!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
1711
1712	return sysfs_emit(buf, "%d\n", val);
1713}
1714BTRFS_ATTR(devid, in_fs_metadata, btrfs_devinfo_in_fs_metadata_show);
1715
1716static ssize_t btrfs_devinfo_missing_show(struct kobject *kobj,
1717					struct kobj_attribute *a, char *buf)
1718{
1719	int val;
1720	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1721						   devid_kobj);
1722
1723	val = !!test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state);
1724
1725	return sysfs_emit(buf, "%d\n", val);
1726}
1727BTRFS_ATTR(devid, missing, btrfs_devinfo_missing_show);
1728
1729static ssize_t btrfs_devinfo_replace_target_show(struct kobject *kobj,
1730					         struct kobj_attribute *a,
1731					         char *buf)
1732{
1733	int val;
1734	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1735						   devid_kobj);
1736
1737	val = !!test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state);
1738
1739	return sysfs_emit(buf, "%d\n", val);
1740}
1741BTRFS_ATTR(devid, replace_target, btrfs_devinfo_replace_target_show);
1742
1743static ssize_t btrfs_devinfo_scrub_speed_max_show(struct kobject *kobj,
1744					     struct kobj_attribute *a,
1745					     char *buf)
1746{
1747	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1748						   devid_kobj);
1749
1750	return sysfs_emit(buf, "%llu\n", READ_ONCE(device->scrub_speed_max));
1751}
1752
1753static ssize_t btrfs_devinfo_scrub_speed_max_store(struct kobject *kobj,
1754					      struct kobj_attribute *a,
1755					      const char *buf, size_t len)
1756{
1757	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1758						   devid_kobj);
1759	char *endptr;
1760	unsigned long long limit;
1761
1762	limit = memparse(buf, &endptr);
1763	/* There could be trailing '\n', also catch any typos after the value. */
1764	endptr = skip_spaces(endptr);
1765	if (*endptr != 0)
1766		return -EINVAL;
1767	WRITE_ONCE(device->scrub_speed_max, limit);
1768	return len;
1769}
1770BTRFS_ATTR_RW(devid, scrub_speed_max, btrfs_devinfo_scrub_speed_max_show,
1771	      btrfs_devinfo_scrub_speed_max_store);
1772
1773static ssize_t btrfs_devinfo_writeable_show(struct kobject *kobj,
1774					    struct kobj_attribute *a, char *buf)
1775{
1776	int val;
1777	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1778						   devid_kobj);
1779
1780	val = !!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
1781
1782	return sysfs_emit(buf, "%d\n", val);
1783}
1784BTRFS_ATTR(devid, writeable, btrfs_devinfo_writeable_show);
1785
1786static ssize_t btrfs_devinfo_fsid_show(struct kobject *kobj,
1787				       struct kobj_attribute *a, char *buf)
1788{
1789	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1790						   devid_kobj);
1791
1792	return sysfs_emit(buf, "%pU\n", device->fs_devices->fsid);
1793}
1794BTRFS_ATTR(devid, fsid, btrfs_devinfo_fsid_show);
1795
1796static ssize_t btrfs_devinfo_error_stats_show(struct kobject *kobj,
1797		struct kobj_attribute *a, char *buf)
1798{
1799	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1800						   devid_kobj);
1801
1802	if (!device->dev_stats_valid)
1803		return sysfs_emit(buf, "invalid\n");
1804
1805	/*
1806	 * Print all at once so we get a snapshot of all values from the same
1807	 * time. Keep them in sync and in order of definition of
1808	 * btrfs_dev_stat_values.
1809	 */
1810	return sysfs_emit(buf,
1811		"write_errs %d\n"
1812		"read_errs %d\n"
1813		"flush_errs %d\n"
1814		"corruption_errs %d\n"
1815		"generation_errs %d\n",
1816		btrfs_dev_stat_read(device, BTRFS_DEV_STAT_WRITE_ERRS),
1817		btrfs_dev_stat_read(device, BTRFS_DEV_STAT_READ_ERRS),
1818		btrfs_dev_stat_read(device, BTRFS_DEV_STAT_FLUSH_ERRS),
1819		btrfs_dev_stat_read(device, BTRFS_DEV_STAT_CORRUPTION_ERRS),
1820		btrfs_dev_stat_read(device, BTRFS_DEV_STAT_GENERATION_ERRS));
1821}
1822BTRFS_ATTR(devid, error_stats, btrfs_devinfo_error_stats_show);
1823
1824/*
1825 * Information about one device.
1826 *
1827 * Path: /sys/fs/btrfs/<uuid>/devinfo/<devid>/
1828 */
1829static struct attribute *devid_attrs[] = {
1830	BTRFS_ATTR_PTR(devid, error_stats),
1831	BTRFS_ATTR_PTR(devid, fsid),
1832	BTRFS_ATTR_PTR(devid, in_fs_metadata),
1833	BTRFS_ATTR_PTR(devid, missing),
1834	BTRFS_ATTR_PTR(devid, replace_target),
1835	BTRFS_ATTR_PTR(devid, scrub_speed_max),
1836	BTRFS_ATTR_PTR(devid, writeable),
1837	NULL
1838};
1839ATTRIBUTE_GROUPS(devid);
1840
1841static void btrfs_release_devid_kobj(struct kobject *kobj)
1842{
1843	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1844						   devid_kobj);
1845
1846	memset(&device->devid_kobj, 0, sizeof(struct kobject));
1847	complete(&device->kobj_unregister);
1848}
1849
1850static const struct kobj_type devid_ktype = {
1851	.sysfs_ops	= &kobj_sysfs_ops,
1852	.default_groups = devid_groups,
1853	.release	= btrfs_release_devid_kobj,
1854};
1855
1856int btrfs_sysfs_add_device(struct btrfs_device *device)
1857{
1858	int ret;
1859	unsigned int nofs_flag;
1860	struct kobject *devices_kobj;
1861	struct kobject *devinfo_kobj;
1862
1863	/*
1864	 * Make sure we use the fs_info::fs_devices to fetch the kobjects even
1865	 * for the seed fs_devices
1866	 */
1867	devices_kobj = device->fs_info->fs_devices->devices_kobj;
1868	devinfo_kobj = device->fs_info->fs_devices->devinfo_kobj;
1869	ASSERT(devices_kobj);
1870	ASSERT(devinfo_kobj);
1871
1872	nofs_flag = memalloc_nofs_save();
1873
1874	if (device->bdev) {
1875		struct kobject *disk_kobj = bdev_kobj(device->bdev);
1876
1877		ret = sysfs_create_link(devices_kobj, disk_kobj, disk_kobj->name);
1878		if (ret) {
1879			btrfs_warn(device->fs_info,
1880				"creating sysfs device link for devid %llu failed: %d",
1881				device->devid, ret);
1882			goto out;
1883		}
1884	}
1885
1886	init_completion(&device->kobj_unregister);
1887	ret = kobject_init_and_add(&device->devid_kobj, &devid_ktype,
1888				   devinfo_kobj, "%llu", device->devid);
1889	if (ret) {
1890		kobject_put(&device->devid_kobj);
1891		btrfs_warn(device->fs_info,
1892			   "devinfo init for devid %llu failed: %d",
1893			   device->devid, ret);
1894	}
1895
1896out:
1897	memalloc_nofs_restore(nofs_flag);
1898	return ret;
1899}
1900
1901static int btrfs_sysfs_add_fs_devices(struct btrfs_fs_devices *fs_devices)
1902{
1903	int ret;
1904	struct btrfs_device *device;
1905	struct btrfs_fs_devices *seed;
1906
1907	list_for_each_entry(device, &fs_devices->devices, dev_list) {
1908		ret = btrfs_sysfs_add_device(device);
1909		if (ret)
1910			goto fail;
1911	}
1912
1913	list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
1914		list_for_each_entry(device, &seed->devices, dev_list) {
1915			ret = btrfs_sysfs_add_device(device);
1916			if (ret)
1917				goto fail;
1918		}
1919	}
1920
1921	return 0;
1922
1923fail:
1924	btrfs_sysfs_remove_fs_devices(fs_devices);
1925	return ret;
1926}
1927
1928void btrfs_kobject_uevent(struct block_device *bdev, enum kobject_action action)
1929{
1930	int ret;
1931
1932	ret = kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, action);
1933	if (ret)
1934		pr_warn("BTRFS: Sending event '%d' to kobject: '%s' (%p): failed\n",
1935			action, kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
1936			&disk_to_dev(bdev->bd_disk)->kobj);
1937}
1938
1939void btrfs_sysfs_update_sprout_fsid(struct btrfs_fs_devices *fs_devices)
1940
1941{
1942	char fsid_buf[BTRFS_UUID_UNPARSED_SIZE];
1943
1944	/*
1945	 * Sprouting changes fsid of the mounted filesystem, rename the fsid
1946	 * directory
1947	 */
1948	snprintf(fsid_buf, BTRFS_UUID_UNPARSED_SIZE, "%pU", fs_devices->fsid);
1949	if (kobject_rename(&fs_devices->fsid_kobj, fsid_buf))
1950		btrfs_warn(fs_devices->fs_info,
1951				"sysfs: failed to create fsid for sprout");
1952}
1953
1954void btrfs_sysfs_update_devid(struct btrfs_device *device)
1955{
1956	char tmp[24];
1957
1958	snprintf(tmp, sizeof(tmp), "%llu", device->devid);
1959
1960	if (kobject_rename(&device->devid_kobj, tmp))
1961		btrfs_warn(device->fs_devices->fs_info,
1962			   "sysfs: failed to update devid for %llu",
1963			   device->devid);
1964}
1965
1966/* /sys/fs/btrfs/ entry */
1967static struct kset *btrfs_kset;
1968
1969/*
1970 * Creates:
1971 *		/sys/fs/btrfs/UUID
1972 *
1973 * Can be called by the device discovery thread.
1974 */
1975int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs)
1976{
1977	int error;
1978
1979	init_completion(&fs_devs->kobj_unregister);
1980	fs_devs->fsid_kobj.kset = btrfs_kset;
1981	error = kobject_init_and_add(&fs_devs->fsid_kobj, &btrfs_ktype, NULL,
1982				     "%pU", fs_devs->fsid);
1983	if (error) {
1984		kobject_put(&fs_devs->fsid_kobj);
1985		return error;
1986	}
1987
1988	fs_devs->devices_kobj = kobject_create_and_add("devices",
1989						       &fs_devs->fsid_kobj);
1990	if (!fs_devs->devices_kobj) {
1991		btrfs_err(fs_devs->fs_info,
1992			  "failed to init sysfs device interface");
1993		btrfs_sysfs_remove_fsid(fs_devs);
1994		return -ENOMEM;
1995	}
1996
1997	fs_devs->devinfo_kobj = kobject_create_and_add("devinfo",
1998						       &fs_devs->fsid_kobj);
1999	if (!fs_devs->devinfo_kobj) {
2000		btrfs_err(fs_devs->fs_info,
2001			  "failed to init sysfs devinfo kobject");
2002		btrfs_sysfs_remove_fsid(fs_devs);
2003		return -ENOMEM;
2004	}
2005
2006	return 0;
2007}
2008
2009int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info)
2010{
2011	int error;
2012	struct btrfs_fs_devices *fs_devs = fs_info->fs_devices;
2013	struct kobject *fsid_kobj = &fs_devs->fsid_kobj;
2014
2015	error = btrfs_sysfs_add_fs_devices(fs_devs);
2016	if (error)
2017		return error;
2018
2019	error = sysfs_create_files(fsid_kobj, btrfs_attrs);
2020	if (error) {
2021		btrfs_sysfs_remove_fs_devices(fs_devs);
2022		return error;
2023	}
2024
2025	error = sysfs_create_group(fsid_kobj,
2026				   &btrfs_feature_attr_group);
2027	if (error)
2028		goto failure;
2029
2030#ifdef CONFIG_BTRFS_DEBUG
2031	fs_info->debug_kobj = kobject_create_and_add("debug", fsid_kobj);
2032	if (!fs_info->debug_kobj) {
2033		error = -ENOMEM;
2034		goto failure;
2035	}
2036
2037	error = sysfs_create_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
2038	if (error)
2039		goto failure;
2040#endif
2041
2042	/* Discard directory */
2043	fs_info->discard_kobj = kobject_create_and_add("discard", fsid_kobj);
2044	if (!fs_info->discard_kobj) {
2045		error = -ENOMEM;
2046		goto failure;
2047	}
2048
2049	error = sysfs_create_files(fs_info->discard_kobj, discard_attrs);
2050	if (error)
2051		goto failure;
2052
2053	error = addrm_unknown_feature_attrs(fs_info, true);
2054	if (error)
2055		goto failure;
2056
2057	error = sysfs_create_link(fsid_kobj, &fs_info->sb->s_bdi->dev->kobj, "bdi");
2058	if (error)
2059		goto failure;
2060
2061	fs_info->space_info_kobj = kobject_create_and_add("allocation",
2062						  fsid_kobj);
2063	if (!fs_info->space_info_kobj) {
2064		error = -ENOMEM;
2065		goto failure;
2066	}
2067
2068	error = sysfs_create_files(fs_info->space_info_kobj, allocation_attrs);
2069	if (error)
2070		goto failure;
2071
2072	return 0;
2073failure:
2074	btrfs_sysfs_remove_mounted(fs_info);
2075	return error;
2076}
2077
2078static ssize_t qgroup_enabled_show(struct kobject *qgroups_kobj,
2079				   struct kobj_attribute *a,
2080				   char *buf)
2081{
2082	struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
2083	bool enabled;
2084
2085	spin_lock(&fs_info->qgroup_lock);
2086	enabled = fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON;
2087	spin_unlock(&fs_info->qgroup_lock);
2088
2089	return sysfs_emit(buf, "%d\n", enabled);
2090}
2091BTRFS_ATTR(qgroups, enabled, qgroup_enabled_show);
2092
2093static ssize_t qgroup_inconsistent_show(struct kobject *qgroups_kobj,
2094					struct kobj_attribute *a,
2095					char *buf)
2096{
2097	struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
2098	bool inconsistent;
2099
2100	spin_lock(&fs_info->qgroup_lock);
2101	inconsistent = (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT);
2102	spin_unlock(&fs_info->qgroup_lock);
2103
2104	return sysfs_emit(buf, "%d\n", inconsistent);
2105}
2106BTRFS_ATTR(qgroups, inconsistent, qgroup_inconsistent_show);
2107
2108static ssize_t qgroup_drop_subtree_thres_show(struct kobject *qgroups_kobj,
2109					      struct kobj_attribute *a,
2110					      char *buf)
2111{
2112	struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
2113	u8 result;
2114
2115	spin_lock(&fs_info->qgroup_lock);
2116	result = fs_info->qgroup_drop_subtree_thres;
2117	spin_unlock(&fs_info->qgroup_lock);
2118
2119	return sysfs_emit(buf, "%d\n", result);
2120}
2121
2122static ssize_t qgroup_drop_subtree_thres_store(struct kobject *qgroups_kobj,
2123					       struct kobj_attribute *a,
2124					       const char *buf, size_t len)
2125{
2126	struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
2127	u8 new_thres;
2128	int ret;
2129
2130	ret = kstrtou8(buf, 10, &new_thres);
2131	if (ret)
2132		return -EINVAL;
2133
2134	if (new_thres > BTRFS_MAX_LEVEL)
2135		return -EINVAL;
2136
2137	spin_lock(&fs_info->qgroup_lock);
2138	fs_info->qgroup_drop_subtree_thres = new_thres;
2139	spin_unlock(&fs_info->qgroup_lock);
2140
2141	return len;
2142}
2143BTRFS_ATTR_RW(qgroups, drop_subtree_threshold, qgroup_drop_subtree_thres_show,
2144	      qgroup_drop_subtree_thres_store);
2145
2146/*
2147 * Qgroups global info
2148 *
2149 * Path: /sys/fs/btrfs/<uuid>/qgroups/
2150 */
2151static struct attribute *qgroups_attrs[] = {
2152	BTRFS_ATTR_PTR(qgroups, enabled),
2153	BTRFS_ATTR_PTR(qgroups, inconsistent),
2154	BTRFS_ATTR_PTR(qgroups, drop_subtree_threshold),
2155	NULL
2156};
2157ATTRIBUTE_GROUPS(qgroups);
2158
2159static void qgroups_release(struct kobject *kobj)
2160{
2161	kfree(kobj);
2162}
2163
2164static const struct kobj_type qgroups_ktype = {
2165	.sysfs_ops = &kobj_sysfs_ops,
2166	.default_groups = qgroups_groups,
2167	.release = qgroups_release,
2168};
2169
2170static inline struct btrfs_fs_info *qgroup_kobj_to_fs_info(struct kobject *kobj)
2171{
2172	return to_fs_info(kobj->parent->parent);
2173}
2174
2175#define QGROUP_ATTR(_member, _show_name)					\
2176static ssize_t btrfs_qgroup_show_##_member(struct kobject *qgroup_kobj,		\
2177					   struct kobj_attribute *a,		\
2178					   char *buf)				\
2179{										\
2180	struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj);	\
2181	struct btrfs_qgroup *qgroup = container_of(qgroup_kobj,			\
2182			struct btrfs_qgroup, kobj);				\
2183	return btrfs_show_u64(&qgroup->_member, &fs_info->qgroup_lock, buf);	\
2184}										\
2185BTRFS_ATTR(qgroup, _show_name, btrfs_qgroup_show_##_member)
2186
2187#define QGROUP_RSV_ATTR(_name, _type)						\
2188static ssize_t btrfs_qgroup_rsv_show_##_name(struct kobject *qgroup_kobj,	\
2189					     struct kobj_attribute *a,		\
2190					     char *buf)				\
2191{										\
2192	struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj);	\
2193	struct btrfs_qgroup *qgroup = container_of(qgroup_kobj,			\
2194			struct btrfs_qgroup, kobj);				\
2195	return btrfs_show_u64(&qgroup->rsv.values[_type],			\
2196			&fs_info->qgroup_lock, buf);				\
2197}										\
2198BTRFS_ATTR(qgroup, rsv_##_name, btrfs_qgroup_rsv_show_##_name)
2199
2200QGROUP_ATTR(rfer, referenced);
2201QGROUP_ATTR(excl, exclusive);
2202QGROUP_ATTR(max_rfer, max_referenced);
2203QGROUP_ATTR(max_excl, max_exclusive);
2204QGROUP_ATTR(lim_flags, limit_flags);
2205QGROUP_RSV_ATTR(data, BTRFS_QGROUP_RSV_DATA);
2206QGROUP_RSV_ATTR(meta_pertrans, BTRFS_QGROUP_RSV_META_PERTRANS);
2207QGROUP_RSV_ATTR(meta_prealloc, BTRFS_QGROUP_RSV_META_PREALLOC);
2208
2209/*
2210 * Qgroup information.
2211 *
2212 * Path: /sys/fs/btrfs/<uuid>/qgroups/<level>_<qgroupid>/
2213 */
2214static struct attribute *qgroup_attrs[] = {
2215	BTRFS_ATTR_PTR(qgroup, referenced),
2216	BTRFS_ATTR_PTR(qgroup, exclusive),
2217	BTRFS_ATTR_PTR(qgroup, max_referenced),
2218	BTRFS_ATTR_PTR(qgroup, max_exclusive),
2219	BTRFS_ATTR_PTR(qgroup, limit_flags),
2220	BTRFS_ATTR_PTR(qgroup, rsv_data),
2221	BTRFS_ATTR_PTR(qgroup, rsv_meta_pertrans),
2222	BTRFS_ATTR_PTR(qgroup, rsv_meta_prealloc),
2223	NULL
2224};
2225ATTRIBUTE_GROUPS(qgroup);
2226
2227static void qgroup_release(struct kobject *kobj)
2228{
2229	struct btrfs_qgroup *qgroup = container_of(kobj, struct btrfs_qgroup, kobj);
2230
2231	memset(&qgroup->kobj, 0, sizeof(*kobj));
2232}
2233
2234static const struct kobj_type qgroup_ktype = {
2235	.sysfs_ops = &kobj_sysfs_ops,
2236	.release = qgroup_release,
2237	.default_groups = qgroup_groups,
2238};
2239
2240int btrfs_sysfs_add_one_qgroup(struct btrfs_fs_info *fs_info,
2241				struct btrfs_qgroup *qgroup)
2242{
2243	struct kobject *qgroups_kobj = fs_info->qgroups_kobj;
2244	int ret;
2245
2246	if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
2247		return 0;
2248	if (qgroup->kobj.state_initialized)
2249		return 0;
2250	if (!qgroups_kobj)
2251		return -EINVAL;
2252
2253	ret = kobject_init_and_add(&qgroup->kobj, &qgroup_ktype, qgroups_kobj,
2254			"%hu_%llu", btrfs_qgroup_level(qgroup->qgroupid),
2255			btrfs_qgroup_subvolid(qgroup->qgroupid));
2256	if (ret < 0)
2257		kobject_put(&qgroup->kobj);
2258
2259	return ret;
2260}
2261
2262void btrfs_sysfs_del_qgroups(struct btrfs_fs_info *fs_info)
2263{
2264	struct btrfs_qgroup *qgroup;
2265	struct btrfs_qgroup *next;
2266
2267	if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
2268		return;
2269
2270	rbtree_postorder_for_each_entry_safe(qgroup, next,
2271					     &fs_info->qgroup_tree, node)
2272		btrfs_sysfs_del_one_qgroup(fs_info, qgroup);
2273	if (fs_info->qgroups_kobj) {
2274		kobject_del(fs_info->qgroups_kobj);
2275		kobject_put(fs_info->qgroups_kobj);
2276		fs_info->qgroups_kobj = NULL;
2277	}
2278}
2279
2280/* Called when qgroups get initialized, thus there is no need for locking */
2281int btrfs_sysfs_add_qgroups(struct btrfs_fs_info *fs_info)
2282{
2283	struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
2284	struct btrfs_qgroup *qgroup;
2285	struct btrfs_qgroup *next;
2286	int ret = 0;
2287
2288	if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
2289		return 0;
2290
2291	ASSERT(fsid_kobj);
2292	if (fs_info->qgroups_kobj)
2293		return 0;
2294
2295	fs_info->qgroups_kobj = kzalloc(sizeof(struct kobject), GFP_KERNEL);
2296	if (!fs_info->qgroups_kobj)
2297		return -ENOMEM;
2298
2299	ret = kobject_init_and_add(fs_info->qgroups_kobj, &qgroups_ktype,
2300				   fsid_kobj, "qgroups");
2301	if (ret < 0)
2302		goto out;
2303
2304	rbtree_postorder_for_each_entry_safe(qgroup, next,
2305					     &fs_info->qgroup_tree, node) {
2306		ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
2307		if (ret < 0)
2308			goto out;
2309	}
2310
2311out:
2312	if (ret < 0)
2313		btrfs_sysfs_del_qgroups(fs_info);
2314	return ret;
2315}
2316
2317void btrfs_sysfs_del_one_qgroup(struct btrfs_fs_info *fs_info,
2318				struct btrfs_qgroup *qgroup)
2319{
2320	if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
2321		return;
2322
2323	if (qgroup->kobj.state_initialized) {
2324		kobject_del(&qgroup->kobj);
2325		kobject_put(&qgroup->kobj);
2326	}
2327}
2328
2329/*
2330 * Change per-fs features in /sys/fs/btrfs/UUID/features to match current
2331 * values in superblock. Call after any changes to incompat/compat_ro flags
2332 */
2333void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info)
2334{
2335	struct kobject *fsid_kobj;
2336	int ret;
2337
2338	if (!fs_info)
2339		return;
2340
2341	fsid_kobj = &fs_info->fs_devices->fsid_kobj;
2342	if (!fsid_kobj->state_initialized)
2343		return;
2344
2345	ret = sysfs_update_group(fsid_kobj, &btrfs_feature_attr_group);
2346	if (ret < 0)
2347		btrfs_warn(fs_info,
2348			   "failed to update /sys/fs/btrfs/%pU/features: %d",
2349			   fs_info->fs_devices->fsid, ret);
2350}
2351
2352int __init btrfs_init_sysfs(void)
2353{
2354	int ret;
2355
2356	btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj);
2357	if (!btrfs_kset)
2358		return -ENOMEM;
2359
2360	init_feature_attrs();
2361	ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2362	if (ret)
2363		goto out2;
2364	ret = sysfs_merge_group(&btrfs_kset->kobj,
2365				&btrfs_static_feature_attr_group);
2366	if (ret)
2367		goto out_remove_group;
2368
2369#ifdef CONFIG_BTRFS_DEBUG
2370	ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
2371	if (ret) {
2372		sysfs_unmerge_group(&btrfs_kset->kobj,
2373				    &btrfs_static_feature_attr_group);
2374		goto out_remove_group;
2375	}
2376#endif
2377
2378	return 0;
2379
2380out_remove_group:
2381	sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2382out2:
2383	kset_unregister(btrfs_kset);
2384
2385	return ret;
2386}
2387
2388void __cold btrfs_exit_sysfs(void)
2389{
2390	sysfs_unmerge_group(&btrfs_kset->kobj,
2391			    &btrfs_static_feature_attr_group);
2392	sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2393#ifdef CONFIG_BTRFS_DEBUG
2394	sysfs_remove_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
2395#endif
2396	kset_unregister(btrfs_kset);
2397}
2398