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(a: 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(s: disk_super);
127 else if (set == FEAT_COMPAT_RO)
128 return btrfs_super_compat_ro_flags(s: disk_super);
129 else
130 return btrfs_super_incompat_flags(s: 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(s: disk_super, val: features);
139 else if (set == FEAT_COMPAT_RO)
140 btrfs_set_super_compat_ro_flags(s: disk_super, val: features);
141 else
142 btrfs_set_super_incompat_flags(s: disk_super, val: 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, 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
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(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
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, 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
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);
294BTRFS_FEAT_ATTR_INCOMPAT(simple_quota, SIMPLE_QUOTA);
295#ifdef CONFIG_BLK_DEV_ZONED
296BTRFS_FEAT_ATTR_INCOMPAT(zoned, ZONED);
297#endif
298#ifdef CONFIG_BTRFS_DEBUG
299/* Remove once support for extent tree v2 is feature complete */
300BTRFS_FEAT_ATTR_INCOMPAT(extent_tree_v2, EXTENT_TREE_V2);
301/* Remove once support for raid stripe tree is feature complete. */
302BTRFS_FEAT_ATTR_INCOMPAT(raid_stripe_tree, RAID_STRIPE_TREE);
303#endif
304#ifdef CONFIG_FS_VERITY
305BTRFS_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 */
315static 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_DEBUG
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
342static 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
348static 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}
353BTRFS_ATTR(static_feature, rmdir_subvol, rmdir_subvol_show);
354
355static 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}
374BTRFS_ATTR(static_feature, supported_checksums, supported_checksums_show);
375
376static 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}
381BTRFS_ATTR(static_feature, send_stream_version, send_stream_version_show);
382
383static const char *rescue_opts[] = {
384 "usebackuproot",
385 "nologreplay",
386 "ignorebadroots",
387 "ignoredatacsums",
388 "all",
389};
390
391static ssize_t supported_rescue_options_show(struct kobject *kobj,
392 struct kobj_attribute *a,
393 char *buf)
394{
395 ssize_t ret = 0;
396 int i;
397
398 for (i = 0; i < ARRAY_SIZE(rescue_opts); i++)
399 ret += sysfs_emit_at(buf, at: ret, fmt: "%s%s", (i ? " " : ""), rescue_opts[i]);
400 ret += sysfs_emit_at(buf, at: ret, fmt: "\n");
401 return ret;
402}
403BTRFS_ATTR(static_feature, supported_rescue_options,
404 supported_rescue_options_show);
405
406static ssize_t supported_sectorsizes_show(struct kobject *kobj,
407 struct kobj_attribute *a,
408 char *buf)
409{
410 ssize_t ret = 0;
411
412 /* An artificial limit to only support 4K and PAGE_SIZE */
413 if (PAGE_SIZE > SZ_4K)
414 ret += sysfs_emit_at(buf, at: ret, fmt: "%u ", SZ_4K);
415 ret += sysfs_emit_at(buf, at: ret, fmt: "%lu\n", PAGE_SIZE);
416
417 return ret;
418}
419BTRFS_ATTR(static_feature, supported_sectorsizes,
420 supported_sectorsizes_show);
421
422static ssize_t acl_show(struct kobject *kobj, struct kobj_attribute *a, char *buf)
423{
424 return sysfs_emit(buf, fmt: "%d\n", !!IS_ENABLED(CONFIG_BTRFS_FS_POSIX_ACL));
425}
426BTRFS_ATTR(static_feature, acl, acl_show);
427
428static ssize_t temp_fsid_supported_show(struct kobject *kobj,
429 struct kobj_attribute *a, char *buf)
430{
431 return sysfs_emit(buf, fmt: "0\n");
432}
433BTRFS_ATTR(static_feature, temp_fsid, temp_fsid_supported_show);
434
435/*
436 * Features which only depend on kernel version.
437 *
438 * These are listed in /sys/fs/btrfs/features along with
439 * btrfs_supported_feature_attrs.
440 */
441static struct attribute *btrfs_supported_static_feature_attrs[] = {
442 BTRFS_ATTR_PTR(static_feature, acl),
443 BTRFS_ATTR_PTR(static_feature, rmdir_subvol),
444 BTRFS_ATTR_PTR(static_feature, supported_checksums),
445 BTRFS_ATTR_PTR(static_feature, send_stream_version),
446 BTRFS_ATTR_PTR(static_feature, supported_rescue_options),
447 BTRFS_ATTR_PTR(static_feature, supported_sectorsizes),
448 BTRFS_ATTR_PTR(static_feature, temp_fsid),
449 NULL
450};
451
452static const struct attribute_group btrfs_static_feature_attr_group = {
453 .name = "features",
454 .attrs = btrfs_supported_static_feature_attrs,
455};
456
457/*
458 * Discard statistics and tunables
459 */
460#define discard_to_fs_info(_kobj) to_fs_info(get_btrfs_kobj(_kobj))
461
462static ssize_t btrfs_discardable_bytes_show(struct kobject *kobj,
463 struct kobj_attribute *a,
464 char *buf)
465{
466 struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
467
468 return sysfs_emit(buf, fmt: "%lld\n",
469 atomic64_read(v: &fs_info->discard_ctl.discardable_bytes));
470}
471BTRFS_ATTR(discard, discardable_bytes, btrfs_discardable_bytes_show);
472
473static ssize_t btrfs_discardable_extents_show(struct kobject *kobj,
474 struct kobj_attribute *a,
475 char *buf)
476{
477 struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
478
479 return sysfs_emit(buf, fmt: "%d\n",
480 atomic_read(v: &fs_info->discard_ctl.discardable_extents));
481}
482BTRFS_ATTR(discard, discardable_extents, btrfs_discardable_extents_show);
483
484static ssize_t btrfs_discard_bitmap_bytes_show(struct kobject *kobj,
485 struct kobj_attribute *a,
486 char *buf)
487{
488 struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
489
490 return sysfs_emit(buf, fmt: "%llu\n",
491 fs_info->discard_ctl.discard_bitmap_bytes);
492}
493BTRFS_ATTR(discard, discard_bitmap_bytes, btrfs_discard_bitmap_bytes_show);
494
495static ssize_t btrfs_discard_bytes_saved_show(struct kobject *kobj,
496 struct kobj_attribute *a,
497 char *buf)
498{
499 struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
500
501 return sysfs_emit(buf, fmt: "%lld\n",
502 atomic64_read(v: &fs_info->discard_ctl.discard_bytes_saved));
503}
504BTRFS_ATTR(discard, discard_bytes_saved, btrfs_discard_bytes_saved_show);
505
506static ssize_t btrfs_discard_extent_bytes_show(struct kobject *kobj,
507 struct kobj_attribute *a,
508 char *buf)
509{
510 struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
511
512 return sysfs_emit(buf, fmt: "%llu\n",
513 fs_info->discard_ctl.discard_extent_bytes);
514}
515BTRFS_ATTR(discard, discard_extent_bytes, btrfs_discard_extent_bytes_show);
516
517static ssize_t btrfs_discard_iops_limit_show(struct kobject *kobj,
518 struct kobj_attribute *a,
519 char *buf)
520{
521 struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
522
523 return sysfs_emit(buf, fmt: "%u\n",
524 READ_ONCE(fs_info->discard_ctl.iops_limit));
525}
526
527static ssize_t btrfs_discard_iops_limit_store(struct kobject *kobj,
528 struct kobj_attribute *a,
529 const char *buf, size_t len)
530{
531 struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
532 struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
533 u32 iops_limit;
534 int ret;
535
536 ret = kstrtou32(s: buf, base: 10, res: &iops_limit);
537 if (ret)
538 return -EINVAL;
539
540 WRITE_ONCE(discard_ctl->iops_limit, iops_limit);
541 btrfs_discard_calc_delay(discard_ctl);
542 btrfs_discard_schedule_work(discard_ctl, override: true);
543 return len;
544}
545BTRFS_ATTR_RW(discard, iops_limit, btrfs_discard_iops_limit_show,
546 btrfs_discard_iops_limit_store);
547
548static ssize_t btrfs_discard_kbps_limit_show(struct kobject *kobj,
549 struct kobj_attribute *a,
550 char *buf)
551{
552 struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
553
554 return sysfs_emit(buf, fmt: "%u\n",
555 READ_ONCE(fs_info->discard_ctl.kbps_limit));
556}
557
558static ssize_t btrfs_discard_kbps_limit_store(struct kobject *kobj,
559 struct kobj_attribute *a,
560 const char *buf, size_t len)
561{
562 struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
563 struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
564 u32 kbps_limit;
565 int ret;
566
567 ret = kstrtou32(s: buf, base: 10, res: &kbps_limit);
568 if (ret)
569 return -EINVAL;
570
571 WRITE_ONCE(discard_ctl->kbps_limit, kbps_limit);
572 btrfs_discard_schedule_work(discard_ctl, override: true);
573 return len;
574}
575BTRFS_ATTR_RW(discard, kbps_limit, btrfs_discard_kbps_limit_show,
576 btrfs_discard_kbps_limit_store);
577
578static ssize_t btrfs_discard_max_discard_size_show(struct kobject *kobj,
579 struct kobj_attribute *a,
580 char *buf)
581{
582 struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
583
584 return sysfs_emit(buf, fmt: "%llu\n",
585 READ_ONCE(fs_info->discard_ctl.max_discard_size));
586}
587
588static ssize_t btrfs_discard_max_discard_size_store(struct kobject *kobj,
589 struct kobj_attribute *a,
590 const char *buf, size_t len)
591{
592 struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
593 struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
594 u64 max_discard_size;
595 int ret;
596
597 ret = kstrtou64(s: buf, base: 10, res: &max_discard_size);
598 if (ret)
599 return -EINVAL;
600
601 WRITE_ONCE(discard_ctl->max_discard_size, max_discard_size);
602
603 return len;
604}
605BTRFS_ATTR_RW(discard, max_discard_size, btrfs_discard_max_discard_size_show,
606 btrfs_discard_max_discard_size_store);
607
608/*
609 * Per-filesystem stats for discard (when mounted with discard=async).
610 *
611 * Path: /sys/fs/btrfs/<uuid>/discard/
612 */
613static const struct attribute *discard_attrs[] = {
614 BTRFS_ATTR_PTR(discard, discardable_bytes),
615 BTRFS_ATTR_PTR(discard, discardable_extents),
616 BTRFS_ATTR_PTR(discard, discard_bitmap_bytes),
617 BTRFS_ATTR_PTR(discard, discard_bytes_saved),
618 BTRFS_ATTR_PTR(discard, discard_extent_bytes),
619 BTRFS_ATTR_PTR(discard, iops_limit),
620 BTRFS_ATTR_PTR(discard, kbps_limit),
621 BTRFS_ATTR_PTR(discard, max_discard_size),
622 NULL,
623};
624
625#ifdef CONFIG_BTRFS_DEBUG
626
627/*
628 * Per-filesystem runtime debugging exported via sysfs.
629 *
630 * Path: /sys/fs/btrfs/UUID/debug/
631 */
632static const struct attribute *btrfs_debug_mount_attrs[] = {
633 NULL,
634};
635
636/*
637 * Runtime debugging exported via sysfs, applies to all mounted filesystems.
638 *
639 * Path: /sys/fs/btrfs/debug
640 */
641static struct attribute *btrfs_debug_feature_attrs[] = {
642 NULL
643};
644
645static const struct attribute_group btrfs_debug_feature_attr_group = {
646 .name = "debug",
647 .attrs = btrfs_debug_feature_attrs,
648};
649
650#endif
651
652static ssize_t btrfs_show_u64(u64 *value_ptr, spinlock_t *lock, char *buf)
653{
654 u64 val;
655 if (lock)
656 spin_lock(lock);
657 val = *value_ptr;
658 if (lock)
659 spin_unlock(lock);
660 return sysfs_emit(buf, fmt: "%llu\n", val);
661}
662
663static ssize_t global_rsv_size_show(struct kobject *kobj,
664 struct kobj_attribute *ka, char *buf)
665{
666 struct btrfs_fs_info *fs_info = to_fs_info(kobj: kobj->parent);
667 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
668 return btrfs_show_u64(value_ptr: &block_rsv->size, lock: &block_rsv->lock, buf);
669}
670BTRFS_ATTR(allocation, global_rsv_size, global_rsv_size_show);
671
672static ssize_t global_rsv_reserved_show(struct kobject *kobj,
673 struct kobj_attribute *a, char *buf)
674{
675 struct btrfs_fs_info *fs_info = to_fs_info(kobj: kobj->parent);
676 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
677 return btrfs_show_u64(value_ptr: &block_rsv->reserved, lock: &block_rsv->lock, buf);
678}
679BTRFS_ATTR(allocation, global_rsv_reserved, global_rsv_reserved_show);
680
681#define to_space_info(_kobj) container_of(_kobj, struct btrfs_space_info, kobj)
682#define to_raid_kobj(_kobj) container_of(_kobj, struct raid_kobject, kobj)
683
684static ssize_t raid_bytes_show(struct kobject *kobj,
685 struct kobj_attribute *attr, char *buf);
686BTRFS_ATTR(raid, total_bytes, raid_bytes_show);
687BTRFS_ATTR(raid, used_bytes, raid_bytes_show);
688
689static ssize_t raid_bytes_show(struct kobject *kobj,
690 struct kobj_attribute *attr, char *buf)
691
692{
693 struct btrfs_space_info *sinfo = to_space_info(kobj->parent);
694 struct btrfs_block_group *block_group;
695 int index = btrfs_bg_flags_to_raid_index(to_raid_kobj(kobj)->flags);
696 u64 val = 0;
697
698 down_read(sem: &sinfo->groups_sem);
699 list_for_each_entry(block_group, &sinfo->block_groups[index], list) {
700 if (&attr->attr == BTRFS_ATTR_PTR(raid, total_bytes))
701 val += block_group->length;
702 else
703 val += block_group->used;
704 }
705 up_read(sem: &sinfo->groups_sem);
706 return sysfs_emit(buf, fmt: "%llu\n", val);
707}
708
709/*
710 * Allocation information about block group profiles.
711 *
712 * Path: /sys/fs/btrfs/<uuid>/allocation/<bg-type>/<bg-profile>/
713 */
714static struct attribute *raid_attrs[] = {
715 BTRFS_ATTR_PTR(raid, total_bytes),
716 BTRFS_ATTR_PTR(raid, used_bytes),
717 NULL
718};
719ATTRIBUTE_GROUPS(raid);
720
721static void release_raid_kobj(struct kobject *kobj)
722{
723 kfree(to_raid_kobj(kobj));
724}
725
726static const struct kobj_type btrfs_raid_ktype = {
727 .sysfs_ops = &kobj_sysfs_ops,
728 .release = release_raid_kobj,
729 .default_groups = raid_groups,
730};
731
732#define SPACE_INFO_ATTR(field) \
733static ssize_t btrfs_space_info_show_##field(struct kobject *kobj, \
734 struct kobj_attribute *a, \
735 char *buf) \
736{ \
737 struct btrfs_space_info *sinfo = to_space_info(kobj); \
738 return btrfs_show_u64(&sinfo->field, &sinfo->lock, buf); \
739} \
740BTRFS_ATTR(space_info, field, btrfs_space_info_show_##field)
741
742static ssize_t btrfs_chunk_size_show(struct kobject *kobj,
743 struct kobj_attribute *a, char *buf)
744{
745 struct btrfs_space_info *sinfo = to_space_info(kobj);
746
747 return sysfs_emit(buf, fmt: "%llu\n", READ_ONCE(sinfo->chunk_size));
748}
749
750/*
751 * Store new chunk size in space info. Can be called on a read-only filesystem.
752 *
753 * If the new chunk size value is larger than 10% of free space it is reduced
754 * to match that limit. Alignment must be to 256M and the system chunk size
755 * cannot be set.
756 */
757static ssize_t btrfs_chunk_size_store(struct kobject *kobj,
758 struct kobj_attribute *a,
759 const char *buf, size_t len)
760{
761 struct btrfs_space_info *space_info = to_space_info(kobj);
762 struct btrfs_fs_info *fs_info = to_fs_info(kobj: get_btrfs_kobj(kobj));
763 char *retptr;
764 u64 val;
765
766 if (!capable(CAP_SYS_ADMIN))
767 return -EPERM;
768
769 if (!fs_info->fs_devices)
770 return -EINVAL;
771
772 if (btrfs_is_zoned(fs_info))
773 return -EINVAL;
774
775 /* System block type must not be changed. */
776 if (space_info->flags & BTRFS_BLOCK_GROUP_SYSTEM)
777 return -EPERM;
778
779 val = memparse(ptr: buf, retptr: &retptr);
780 /* There could be trailing '\n', also catch any typos after the value */
781 retptr = skip_spaces(retptr);
782 if (*retptr != 0 || val == 0)
783 return -EINVAL;
784
785 val = min(val, BTRFS_MAX_DATA_CHUNK_SIZE);
786
787 /* Limit stripe size to 10% of available space. */
788 val = min(mult_perc(fs_info->fs_devices->total_rw_bytes, 10), val);
789
790 /* Must be multiple of 256M. */
791 val &= ~((u64)SZ_256M - 1);
792
793 /* Must be at least 256M. */
794 if (val < SZ_256M)
795 return -EINVAL;
796
797 btrfs_update_space_info_chunk_size(space_info, chunk_size: val);
798
799 return len;
800}
801
802static ssize_t btrfs_size_classes_show(struct kobject *kobj,
803 struct kobj_attribute *a, char *buf)
804{
805 struct btrfs_space_info *sinfo = to_space_info(kobj);
806 struct btrfs_block_group *bg;
807 u32 none = 0;
808 u32 small = 0;
809 u32 medium = 0;
810 u32 large = 0;
811
812 for (int i = 0; i < BTRFS_NR_RAID_TYPES; ++i) {
813 down_read(sem: &sinfo->groups_sem);
814 list_for_each_entry(bg, &sinfo->block_groups[i], list) {
815 if (!btrfs_block_group_should_use_size_class(bg))
816 continue;
817 switch (bg->size_class) {
818 case BTRFS_BG_SZ_NONE:
819 none++;
820 break;
821 case BTRFS_BG_SZ_SMALL:
822 small++;
823 break;
824 case BTRFS_BG_SZ_MEDIUM:
825 medium++;
826 break;
827 case BTRFS_BG_SZ_LARGE:
828 large++;
829 break;
830 }
831 }
832 up_read(sem: &sinfo->groups_sem);
833 }
834 return sysfs_emit(buf, fmt: "none %u\n"
835 "small %u\n"
836 "medium %u\n"
837 "large %u\n",
838 none, small, medium, large);
839}
840
841#ifdef CONFIG_BTRFS_DEBUG
842/*
843 * Request chunk allocation with current chunk size.
844 */
845static ssize_t btrfs_force_chunk_alloc_store(struct kobject *kobj,
846 struct kobj_attribute *a,
847 const char *buf, size_t len)
848{
849 struct btrfs_space_info *space_info = to_space_info(kobj);
850 struct btrfs_fs_info *fs_info = to_fs_info(kobj: get_btrfs_kobj(kobj));
851 struct btrfs_trans_handle *trans;
852 bool val;
853 int ret;
854
855 if (!capable(CAP_SYS_ADMIN))
856 return -EPERM;
857
858 if (sb_rdonly(sb: fs_info->sb))
859 return -EROFS;
860
861 ret = kstrtobool(s: buf, res: &val);
862 if (ret)
863 return ret;
864
865 if (!val)
866 return -EINVAL;
867
868 /*
869 * This is unsafe to be called from sysfs context and may cause
870 * unexpected problems.
871 */
872 trans = btrfs_start_transaction(root: fs_info->tree_root, num_items: 0);
873 if (IS_ERR(ptr: trans))
874 return PTR_ERR(ptr: trans);
875 ret = btrfs_force_chunk_alloc(trans, type: space_info->flags);
876 btrfs_end_transaction(trans);
877
878 if (ret == 1)
879 return len;
880
881 return -ENOSPC;
882}
883BTRFS_ATTR_W(space_info, force_chunk_alloc, btrfs_force_chunk_alloc_store);
884
885#endif
886
887SPACE_INFO_ATTR(flags);
888SPACE_INFO_ATTR(total_bytes);
889SPACE_INFO_ATTR(bytes_used);
890SPACE_INFO_ATTR(bytes_pinned);
891SPACE_INFO_ATTR(bytes_reserved);
892SPACE_INFO_ATTR(bytes_may_use);
893SPACE_INFO_ATTR(bytes_readonly);
894SPACE_INFO_ATTR(bytes_zone_unusable);
895SPACE_INFO_ATTR(disk_used);
896SPACE_INFO_ATTR(disk_total);
897BTRFS_ATTR_RW(space_info, chunk_size, btrfs_chunk_size_show, btrfs_chunk_size_store);
898BTRFS_ATTR(space_info, size_classes, btrfs_size_classes_show);
899
900static ssize_t btrfs_sinfo_bg_reclaim_threshold_show(struct kobject *kobj,
901 struct kobj_attribute *a,
902 char *buf)
903{
904 struct btrfs_space_info *space_info = to_space_info(kobj);
905
906 return sysfs_emit(buf, fmt: "%d\n", READ_ONCE(space_info->bg_reclaim_threshold));
907}
908
909static ssize_t btrfs_sinfo_bg_reclaim_threshold_store(struct kobject *kobj,
910 struct kobj_attribute *a,
911 const char *buf, size_t len)
912{
913 struct btrfs_space_info *space_info = to_space_info(kobj);
914 int thresh;
915 int ret;
916
917 ret = kstrtoint(s: buf, base: 10, res: &thresh);
918 if (ret)
919 return ret;
920
921 if (thresh < 0 || thresh > 100)
922 return -EINVAL;
923
924 WRITE_ONCE(space_info->bg_reclaim_threshold, thresh);
925
926 return len;
927}
928
929BTRFS_ATTR_RW(space_info, bg_reclaim_threshold,
930 btrfs_sinfo_bg_reclaim_threshold_show,
931 btrfs_sinfo_bg_reclaim_threshold_store);
932
933/*
934 * Allocation information about block group types.
935 *
936 * Path: /sys/fs/btrfs/<uuid>/allocation/<bg-type>/
937 */
938static struct attribute *space_info_attrs[] = {
939 BTRFS_ATTR_PTR(space_info, flags),
940 BTRFS_ATTR_PTR(space_info, total_bytes),
941 BTRFS_ATTR_PTR(space_info, bytes_used),
942 BTRFS_ATTR_PTR(space_info, bytes_pinned),
943 BTRFS_ATTR_PTR(space_info, bytes_reserved),
944 BTRFS_ATTR_PTR(space_info, bytes_may_use),
945 BTRFS_ATTR_PTR(space_info, bytes_readonly),
946 BTRFS_ATTR_PTR(space_info, bytes_zone_unusable),
947 BTRFS_ATTR_PTR(space_info, disk_used),
948 BTRFS_ATTR_PTR(space_info, disk_total),
949 BTRFS_ATTR_PTR(space_info, bg_reclaim_threshold),
950 BTRFS_ATTR_PTR(space_info, chunk_size),
951 BTRFS_ATTR_PTR(space_info, size_classes),
952#ifdef CONFIG_BTRFS_DEBUG
953 BTRFS_ATTR_PTR(space_info, force_chunk_alloc),
954#endif
955 NULL,
956};
957ATTRIBUTE_GROUPS(space_info);
958
959static void space_info_release(struct kobject *kobj)
960{
961 struct btrfs_space_info *sinfo = to_space_info(kobj);
962 kfree(objp: sinfo);
963}
964
965static const struct kobj_type space_info_ktype = {
966 .sysfs_ops = &kobj_sysfs_ops,
967 .release = space_info_release,
968 .default_groups = space_info_groups,
969};
970
971/*
972 * Allocation information about block groups.
973 *
974 * Path: /sys/fs/btrfs/<uuid>/allocation/
975 */
976static const struct attribute *allocation_attrs[] = {
977 BTRFS_ATTR_PTR(allocation, global_rsv_reserved),
978 BTRFS_ATTR_PTR(allocation, global_rsv_size),
979 NULL,
980};
981
982static ssize_t btrfs_label_show(struct kobject *kobj,
983 struct kobj_attribute *a, char *buf)
984{
985 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
986 char *label = fs_info->super_copy->label;
987 ssize_t ret;
988
989 spin_lock(lock: &fs_info->super_lock);
990 ret = sysfs_emit(buf, fmt: label[0] ? "%s\n" : "%s", label);
991 spin_unlock(lock: &fs_info->super_lock);
992
993 return ret;
994}
995
996static ssize_t btrfs_label_store(struct kobject *kobj,
997 struct kobj_attribute *a,
998 const char *buf, size_t len)
999{
1000 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1001 size_t p_len;
1002
1003 if (!fs_info)
1004 return -EPERM;
1005
1006 if (sb_rdonly(sb: fs_info->sb))
1007 return -EROFS;
1008
1009 /*
1010 * p_len is the len until the first occurrence of either
1011 * '\n' or '\0'
1012 */
1013 p_len = strcspn(buf, "\n");
1014
1015 if (p_len >= BTRFS_LABEL_SIZE)
1016 return -EINVAL;
1017
1018 spin_lock(lock: &fs_info->super_lock);
1019 memset(fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE);
1020 memcpy(fs_info->super_copy->label, buf, p_len);
1021 spin_unlock(lock: &fs_info->super_lock);
1022
1023 /*
1024 * We don't want to do full transaction commit from inside sysfs
1025 */
1026 set_bit(nr: BTRFS_FS_NEED_TRANS_COMMIT, addr: &fs_info->flags);
1027 wake_up_process(tsk: fs_info->transaction_kthread);
1028
1029 return len;
1030}
1031BTRFS_ATTR_RW(, label, btrfs_label_show, btrfs_label_store);
1032
1033static ssize_t btrfs_nodesize_show(struct kobject *kobj,
1034 struct kobj_attribute *a, char *buf)
1035{
1036 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1037
1038 return sysfs_emit(buf, fmt: "%u\n", fs_info->super_copy->nodesize);
1039}
1040
1041BTRFS_ATTR(, nodesize, btrfs_nodesize_show);
1042
1043static ssize_t btrfs_sectorsize_show(struct kobject *kobj,
1044 struct kobj_attribute *a, char *buf)
1045{
1046 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1047
1048 return sysfs_emit(buf, fmt: "%u\n", fs_info->super_copy->sectorsize);
1049}
1050
1051BTRFS_ATTR(, sectorsize, btrfs_sectorsize_show);
1052
1053static ssize_t btrfs_commit_stats_show(struct kobject *kobj,
1054 struct kobj_attribute *a, char *buf)
1055{
1056 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1057
1058 return sysfs_emit(buf,
1059 fmt: "commits %llu\n"
1060 "last_commit_ms %llu\n"
1061 "max_commit_ms %llu\n"
1062 "total_commit_ms %llu\n",
1063 fs_info->commit_stats.commit_count,
1064 div_u64(dividend: fs_info->commit_stats.last_commit_dur, NSEC_PER_MSEC),
1065 div_u64(dividend: fs_info->commit_stats.max_commit_dur, NSEC_PER_MSEC),
1066 div_u64(dividend: fs_info->commit_stats.total_commit_dur, NSEC_PER_MSEC));
1067}
1068
1069static ssize_t btrfs_commit_stats_store(struct kobject *kobj,
1070 struct kobj_attribute *a,
1071 const char *buf, size_t len)
1072{
1073 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1074 unsigned long val;
1075 int ret;
1076
1077 if (!fs_info)
1078 return -EPERM;
1079
1080 if (!capable(CAP_SYS_RESOURCE))
1081 return -EPERM;
1082
1083 ret = kstrtoul(s: buf, base: 10, res: &val);
1084 if (ret)
1085 return ret;
1086 if (val)
1087 return -EINVAL;
1088
1089 WRITE_ONCE(fs_info->commit_stats.max_commit_dur, 0);
1090
1091 return len;
1092}
1093BTRFS_ATTR_RW(, commit_stats, btrfs_commit_stats_show, btrfs_commit_stats_store);
1094
1095static ssize_t btrfs_clone_alignment_show(struct kobject *kobj,
1096 struct kobj_attribute *a, char *buf)
1097{
1098 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1099
1100 return sysfs_emit(buf, fmt: "%u\n", fs_info->super_copy->sectorsize);
1101}
1102
1103BTRFS_ATTR(, clone_alignment, btrfs_clone_alignment_show);
1104
1105static ssize_t quota_override_show(struct kobject *kobj,
1106 struct kobj_attribute *a, char *buf)
1107{
1108 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1109 int quota_override;
1110
1111 quota_override = test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
1112 return sysfs_emit(buf, fmt: "%d\n", quota_override);
1113}
1114
1115static ssize_t quota_override_store(struct kobject *kobj,
1116 struct kobj_attribute *a,
1117 const char *buf, size_t len)
1118{
1119 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1120 unsigned long knob;
1121 int err;
1122
1123 if (!fs_info)
1124 return -EPERM;
1125
1126 if (!capable(CAP_SYS_RESOURCE))
1127 return -EPERM;
1128
1129 err = kstrtoul(s: buf, base: 10, res: &knob);
1130 if (err)
1131 return err;
1132 if (knob > 1)
1133 return -EINVAL;
1134
1135 if (knob)
1136 set_bit(nr: BTRFS_FS_QUOTA_OVERRIDE, addr: &fs_info->flags);
1137 else
1138 clear_bit(nr: BTRFS_FS_QUOTA_OVERRIDE, addr: &fs_info->flags);
1139
1140 return len;
1141}
1142
1143BTRFS_ATTR_RW(, quota_override, quota_override_show, quota_override_store);
1144
1145static ssize_t btrfs_metadata_uuid_show(struct kobject *kobj,
1146 struct kobj_attribute *a, char *buf)
1147{
1148 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1149
1150 return sysfs_emit(buf, fmt: "%pU\n", fs_info->fs_devices->metadata_uuid);
1151}
1152
1153BTRFS_ATTR(, metadata_uuid, btrfs_metadata_uuid_show);
1154
1155static ssize_t btrfs_checksum_show(struct kobject *kobj,
1156 struct kobj_attribute *a, char *buf)
1157{
1158 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1159 u16 csum_type = btrfs_super_csum_type(s: fs_info->super_copy);
1160
1161 return sysfs_emit(buf, fmt: "%s (%s)\n",
1162 btrfs_super_csum_name(csum_type),
1163 crypto_shash_driver_name(tfm: fs_info->csum_shash));
1164}
1165
1166BTRFS_ATTR(, checksum, btrfs_checksum_show);
1167
1168static ssize_t btrfs_exclusive_operation_show(struct kobject *kobj,
1169 struct kobj_attribute *a, char *buf)
1170{
1171 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1172 const char *str;
1173
1174 switch (READ_ONCE(fs_info->exclusive_operation)) {
1175 case BTRFS_EXCLOP_NONE:
1176 str = "none\n";
1177 break;
1178 case BTRFS_EXCLOP_BALANCE:
1179 str = "balance\n";
1180 break;
1181 case BTRFS_EXCLOP_BALANCE_PAUSED:
1182 str = "balance paused\n";
1183 break;
1184 case BTRFS_EXCLOP_DEV_ADD:
1185 str = "device add\n";
1186 break;
1187 case BTRFS_EXCLOP_DEV_REMOVE:
1188 str = "device remove\n";
1189 break;
1190 case BTRFS_EXCLOP_DEV_REPLACE:
1191 str = "device replace\n";
1192 break;
1193 case BTRFS_EXCLOP_RESIZE:
1194 str = "resize\n";
1195 break;
1196 case BTRFS_EXCLOP_SWAP_ACTIVATE:
1197 str = "swap activate\n";
1198 break;
1199 default:
1200 str = "UNKNOWN\n";
1201 break;
1202 }
1203 return sysfs_emit(buf, fmt: "%s", str);
1204}
1205BTRFS_ATTR(, exclusive_operation, btrfs_exclusive_operation_show);
1206
1207static ssize_t btrfs_generation_show(struct kobject *kobj,
1208 struct kobj_attribute *a, char *buf)
1209{
1210 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1211
1212 return sysfs_emit(buf, fmt: "%llu\n", btrfs_get_fs_generation(fs_info));
1213}
1214BTRFS_ATTR(, generation, btrfs_generation_show);
1215
1216static ssize_t btrfs_temp_fsid_show(struct kobject *kobj,
1217 struct kobj_attribute *a, char *buf)
1218{
1219 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1220
1221 return sysfs_emit(buf, fmt: "%d\n", fs_info->fs_devices->temp_fsid);
1222}
1223BTRFS_ATTR(, temp_fsid, btrfs_temp_fsid_show);
1224
1225static const char * const btrfs_read_policy_name[] = { "pid" };
1226
1227static ssize_t btrfs_read_policy_show(struct kobject *kobj,
1228 struct kobj_attribute *a, char *buf)
1229{
1230 struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
1231 ssize_t ret = 0;
1232 int i;
1233
1234 for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
1235 if (fs_devices->read_policy == i)
1236 ret += sysfs_emit_at(buf, at: ret, fmt: "%s[%s]",
1237 (ret == 0 ? "" : " "),
1238 btrfs_read_policy_name[i]);
1239 else
1240 ret += sysfs_emit_at(buf, at: ret, fmt: "%s%s",
1241 (ret == 0 ? "" : " "),
1242 btrfs_read_policy_name[i]);
1243 }
1244
1245 ret += sysfs_emit_at(buf, at: ret, fmt: "\n");
1246
1247 return ret;
1248}
1249
1250static ssize_t btrfs_read_policy_store(struct kobject *kobj,
1251 struct kobj_attribute *a,
1252 const char *buf, size_t len)
1253{
1254 struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
1255 int i;
1256
1257 for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
1258 if (sysfs_streq(s1: buf, s2: btrfs_read_policy_name[i])) {
1259 if (i != fs_devices->read_policy) {
1260 fs_devices->read_policy = i;
1261 btrfs_info(fs_devices->fs_info,
1262 "read policy set to '%s'",
1263 btrfs_read_policy_name[i]);
1264 }
1265 return len;
1266 }
1267 }
1268
1269 return -EINVAL;
1270}
1271BTRFS_ATTR_RW(, read_policy, btrfs_read_policy_show, btrfs_read_policy_store);
1272
1273static ssize_t btrfs_bg_reclaim_threshold_show(struct kobject *kobj,
1274 struct kobj_attribute *a,
1275 char *buf)
1276{
1277 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1278
1279 return sysfs_emit(buf, fmt: "%d\n", READ_ONCE(fs_info->bg_reclaim_threshold));
1280}
1281
1282static ssize_t btrfs_bg_reclaim_threshold_store(struct kobject *kobj,
1283 struct kobj_attribute *a,
1284 const char *buf, size_t len)
1285{
1286 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1287 int thresh;
1288 int ret;
1289
1290 ret = kstrtoint(s: buf, base: 10, res: &thresh);
1291 if (ret)
1292 return ret;
1293
1294#ifdef CONFIG_BTRFS_DEBUG
1295 if (thresh != 0 && (thresh > 100))
1296 return -EINVAL;
1297#else
1298 if (thresh != 0 && (thresh <= 50 || thresh > 100))
1299 return -EINVAL;
1300#endif
1301
1302 WRITE_ONCE(fs_info->bg_reclaim_threshold, thresh);
1303
1304 return len;
1305}
1306BTRFS_ATTR_RW(, bg_reclaim_threshold, btrfs_bg_reclaim_threshold_show,
1307 btrfs_bg_reclaim_threshold_store);
1308
1309/*
1310 * Per-filesystem information and stats.
1311 *
1312 * Path: /sys/fs/btrfs/<uuid>/
1313 */
1314static const struct attribute *btrfs_attrs[] = {
1315 BTRFS_ATTR_PTR(, label),
1316 BTRFS_ATTR_PTR(, nodesize),
1317 BTRFS_ATTR_PTR(, sectorsize),
1318 BTRFS_ATTR_PTR(, clone_alignment),
1319 BTRFS_ATTR_PTR(, quota_override),
1320 BTRFS_ATTR_PTR(, metadata_uuid),
1321 BTRFS_ATTR_PTR(, checksum),
1322 BTRFS_ATTR_PTR(, exclusive_operation),
1323 BTRFS_ATTR_PTR(, generation),
1324 BTRFS_ATTR_PTR(, read_policy),
1325 BTRFS_ATTR_PTR(, bg_reclaim_threshold),
1326 BTRFS_ATTR_PTR(, commit_stats),
1327 BTRFS_ATTR_PTR(, temp_fsid),
1328 NULL,
1329};
1330
1331static void btrfs_release_fsid_kobj(struct kobject *kobj)
1332{
1333 struct btrfs_fs_devices *fs_devs = to_fs_devs(kobj);
1334
1335 memset(&fs_devs->fsid_kobj, 0, sizeof(struct kobject));
1336 complete(&fs_devs->kobj_unregister);
1337}
1338
1339static const struct kobj_type btrfs_ktype = {
1340 .sysfs_ops = &kobj_sysfs_ops,
1341 .release = btrfs_release_fsid_kobj,
1342};
1343
1344static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj)
1345{
1346 if (kobj->ktype != &btrfs_ktype)
1347 return NULL;
1348 return container_of(kobj, struct btrfs_fs_devices, fsid_kobj);
1349}
1350
1351static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)
1352{
1353 if (kobj->ktype != &btrfs_ktype)
1354 return NULL;
1355 return to_fs_devs(kobj)->fs_info;
1356}
1357
1358static struct kobject *get_btrfs_kobj(struct kobject *kobj)
1359{
1360 while (kobj) {
1361 if (kobj->ktype == &btrfs_ktype)
1362 return kobj;
1363 kobj = kobj->parent;
1364 }
1365 return NULL;
1366}
1367
1368#define NUM_FEATURE_BITS 64
1369#define BTRFS_FEATURE_NAME_MAX 13
1370static char btrfs_unknown_feature_names[FEAT_MAX][NUM_FEATURE_BITS][BTRFS_FEATURE_NAME_MAX];
1371static struct btrfs_feature_attr btrfs_feature_attrs[FEAT_MAX][NUM_FEATURE_BITS];
1372
1373static_assert(ARRAY_SIZE(btrfs_unknown_feature_names) ==
1374 ARRAY_SIZE(btrfs_feature_attrs));
1375static_assert(ARRAY_SIZE(btrfs_unknown_feature_names[0]) ==
1376 ARRAY_SIZE(btrfs_feature_attrs[0]));
1377
1378static const u64 supported_feature_masks[FEAT_MAX] = {
1379 [FEAT_COMPAT] = BTRFS_FEATURE_COMPAT_SUPP,
1380 [FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP,
1381 [FEAT_INCOMPAT] = BTRFS_FEATURE_INCOMPAT_SUPP,
1382};
1383
1384static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add)
1385{
1386 int set;
1387
1388 for (set = 0; set < FEAT_MAX; set++) {
1389 int i;
1390 struct attribute *attrs[2];
1391 struct attribute_group agroup = {
1392 .name = "features",
1393 .attrs = attrs,
1394 };
1395 u64 features = get_features(fs_info, set);
1396 features &= ~supported_feature_masks[set];
1397
1398 if (!features)
1399 continue;
1400
1401 attrs[1] = NULL;
1402 for (i = 0; i < NUM_FEATURE_BITS; i++) {
1403 struct btrfs_feature_attr *fa;
1404
1405 if (!(features & (1ULL << i)))
1406 continue;
1407
1408 fa = &btrfs_feature_attrs[set][i];
1409 attrs[0] = &fa->kobj_attr.attr;
1410 if (add) {
1411 int ret;
1412 ret = sysfs_merge_group(kobj: &fs_info->fs_devices->fsid_kobj,
1413 grp: &agroup);
1414 if (ret)
1415 return ret;
1416 } else
1417 sysfs_unmerge_group(kobj: &fs_info->fs_devices->fsid_kobj,
1418 grp: &agroup);
1419 }
1420
1421 }
1422 return 0;
1423}
1424
1425static void __btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1426{
1427 if (fs_devs->devinfo_kobj) {
1428 kobject_del(kobj: fs_devs->devinfo_kobj);
1429 kobject_put(kobj: fs_devs->devinfo_kobj);
1430 fs_devs->devinfo_kobj = NULL;
1431 }
1432
1433 if (fs_devs->devices_kobj) {
1434 kobject_del(kobj: fs_devs->devices_kobj);
1435 kobject_put(kobj: fs_devs->devices_kobj);
1436 fs_devs->devices_kobj = NULL;
1437 }
1438
1439 if (fs_devs->fsid_kobj.state_initialized) {
1440 kobject_del(kobj: &fs_devs->fsid_kobj);
1441 kobject_put(kobj: &fs_devs->fsid_kobj);
1442 wait_for_completion(&fs_devs->kobj_unregister);
1443 }
1444}
1445
1446/* when fs_devs is NULL it will remove all fsid kobject */
1447void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1448{
1449 struct list_head *fs_uuids = btrfs_get_fs_uuids();
1450
1451 if (fs_devs) {
1452 __btrfs_sysfs_remove_fsid(fs_devs);
1453 return;
1454 }
1455
1456 list_for_each_entry(fs_devs, fs_uuids, fs_list) {
1457 __btrfs_sysfs_remove_fsid(fs_devs);
1458 }
1459}
1460
1461static void btrfs_sysfs_remove_fs_devices(struct btrfs_fs_devices *fs_devices)
1462{
1463 struct btrfs_device *device;
1464 struct btrfs_fs_devices *seed;
1465
1466 list_for_each_entry(device, &fs_devices->devices, dev_list)
1467 btrfs_sysfs_remove_device(device);
1468
1469 list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
1470 list_for_each_entry(device, &seed->devices, dev_list)
1471 btrfs_sysfs_remove_device(device);
1472 }
1473}
1474
1475void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info)
1476{
1477 struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
1478
1479 sysfs_remove_link(kobj: fsid_kobj, name: "bdi");
1480
1481 if (fs_info->space_info_kobj) {
1482 sysfs_remove_files(kobj: fs_info->space_info_kobj, attr: allocation_attrs);
1483 kobject_del(kobj: fs_info->space_info_kobj);
1484 kobject_put(kobj: fs_info->space_info_kobj);
1485 }
1486 if (fs_info->discard_kobj) {
1487 sysfs_remove_files(kobj: fs_info->discard_kobj, attr: discard_attrs);
1488 kobject_del(kobj: fs_info->discard_kobj);
1489 kobject_put(kobj: fs_info->discard_kobj);
1490 }
1491#ifdef CONFIG_BTRFS_DEBUG
1492 if (fs_info->debug_kobj) {
1493 sysfs_remove_files(kobj: fs_info->debug_kobj, attr: btrfs_debug_mount_attrs);
1494 kobject_del(kobj: fs_info->debug_kobj);
1495 kobject_put(kobj: fs_info->debug_kobj);
1496 }
1497#endif
1498 addrm_unknown_feature_attrs(fs_info, add: false);
1499 sysfs_remove_group(kobj: fsid_kobj, grp: &btrfs_feature_attr_group);
1500 sysfs_remove_files(kobj: fsid_kobj, attr: btrfs_attrs);
1501 btrfs_sysfs_remove_fs_devices(fs_devices: fs_info->fs_devices);
1502}
1503
1504static const char * const btrfs_feature_set_names[FEAT_MAX] = {
1505 [FEAT_COMPAT] = "compat",
1506 [FEAT_COMPAT_RO] = "compat_ro",
1507 [FEAT_INCOMPAT] = "incompat",
1508};
1509
1510const char *btrfs_feature_set_name(enum btrfs_feature_set set)
1511{
1512 return btrfs_feature_set_names[set];
1513}
1514
1515char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags)
1516{
1517 size_t bufsize = 4096; /* safe max, 64 names * 64 bytes */
1518 int len = 0;
1519 int i;
1520 char *str;
1521
1522 str = kmalloc(size: bufsize, GFP_KERNEL);
1523 if (!str)
1524 return str;
1525
1526 for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1527 const char *name;
1528
1529 if (!(flags & (1ULL << i)))
1530 continue;
1531
1532 name = btrfs_feature_attrs[set][i].kobj_attr.attr.name;
1533 len += scnprintf(buf: str + len, size: bufsize - len, fmt: "%s%s",
1534 len ? "," : "", name);
1535 }
1536
1537 return str;
1538}
1539
1540static void init_feature_attrs(void)
1541{
1542 struct btrfs_feature_attr *fa;
1543 int set, i;
1544
1545 memset(btrfs_feature_attrs, 0, sizeof(btrfs_feature_attrs));
1546 memset(btrfs_unknown_feature_names, 0,
1547 sizeof(btrfs_unknown_feature_names));
1548
1549 for (i = 0; btrfs_supported_feature_attrs[i]; i++) {
1550 struct btrfs_feature_attr *sfa;
1551 struct attribute *a = btrfs_supported_feature_attrs[i];
1552 int bit;
1553 sfa = attr_to_btrfs_feature_attr(attr: a);
1554 bit = ilog2(sfa->feature_bit);
1555 fa = &btrfs_feature_attrs[sfa->feature_set][bit];
1556
1557 fa->kobj_attr.attr.name = sfa->kobj_attr.attr.name;
1558 }
1559
1560 for (set = 0; set < FEAT_MAX; set++) {
1561 for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1562 char *name = btrfs_unknown_feature_names[set][i];
1563 fa = &btrfs_feature_attrs[set][i];
1564
1565 if (fa->kobj_attr.attr.name)
1566 continue;
1567
1568 snprintf(buf: name, BTRFS_FEATURE_NAME_MAX, fmt: "%s:%u",
1569 btrfs_feature_set_names[set], i);
1570
1571 fa->kobj_attr.attr.name = name;
1572 fa->kobj_attr.attr.mode = S_IRUGO;
1573 fa->feature_set = set;
1574 fa->feature_bit = 1ULL << i;
1575 }
1576 }
1577}
1578
1579/*
1580 * Create a sysfs entry for a given block group type at path
1581 * /sys/fs/btrfs/UUID/allocation/data/TYPE
1582 */
1583void btrfs_sysfs_add_block_group_type(struct btrfs_block_group *cache)
1584{
1585 struct btrfs_fs_info *fs_info = cache->fs_info;
1586 struct btrfs_space_info *space_info = cache->space_info;
1587 struct raid_kobject *rkobj;
1588 const int index = btrfs_bg_flags_to_raid_index(flags: cache->flags);
1589 unsigned int nofs_flag;
1590 int ret;
1591
1592 /*
1593 * Setup a NOFS context because kobject_add(), deep in its call chain,
1594 * does GFP_KERNEL allocations, and we are often called in a context
1595 * where if reclaim is triggered we can deadlock (we are either holding
1596 * a transaction handle or some lock required for a transaction
1597 * commit).
1598 */
1599 nofs_flag = memalloc_nofs_save();
1600
1601 rkobj = kzalloc(size: sizeof(*rkobj), GFP_NOFS);
1602 if (!rkobj) {
1603 memalloc_nofs_restore(flags: nofs_flag);
1604 btrfs_warn(cache->fs_info,
1605 "couldn't alloc memory for raid level kobject");
1606 return;
1607 }
1608
1609 rkobj->flags = cache->flags;
1610 kobject_init(kobj: &rkobj->kobj, ktype: &btrfs_raid_ktype);
1611
1612 /*
1613 * We call this either on mount, or if we've created a block group for a
1614 * new index type while running (i.e. when restriping). The running
1615 * case is tricky because we could race with other threads, so we need
1616 * to have this check to make sure we didn't already init the kobject.
1617 *
1618 * We don't have to protect on the free side because it only happens on
1619 * unmount.
1620 */
1621 spin_lock(lock: &space_info->lock);
1622 if (space_info->block_group_kobjs[index]) {
1623 spin_unlock(lock: &space_info->lock);
1624 kobject_put(kobj: &rkobj->kobj);
1625 return;
1626 } else {
1627 space_info->block_group_kobjs[index] = &rkobj->kobj;
1628 }
1629 spin_unlock(lock: &space_info->lock);
1630
1631 ret = kobject_add(kobj: &rkobj->kobj, parent: &space_info->kobj, fmt: "%s",
1632 btrfs_bg_type_to_raid_name(flags: rkobj->flags));
1633 memalloc_nofs_restore(flags: nofs_flag);
1634 if (ret) {
1635 spin_lock(lock: &space_info->lock);
1636 space_info->block_group_kobjs[index] = NULL;
1637 spin_unlock(lock: &space_info->lock);
1638 kobject_put(kobj: &rkobj->kobj);
1639 btrfs_warn(fs_info,
1640 "failed to add kobject for block cache, ignoring");
1641 return;
1642 }
1643}
1644
1645/*
1646 * Remove sysfs directories for all block group types of a given space info and
1647 * the space info as well
1648 */
1649void btrfs_sysfs_remove_space_info(struct btrfs_space_info *space_info)
1650{
1651 int i;
1652
1653 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
1654 struct kobject *kobj;
1655
1656 kobj = space_info->block_group_kobjs[i];
1657 space_info->block_group_kobjs[i] = NULL;
1658 if (kobj) {
1659 kobject_del(kobj);
1660 kobject_put(kobj);
1661 }
1662 }
1663 kobject_del(kobj: &space_info->kobj);
1664 kobject_put(kobj: &space_info->kobj);
1665}
1666
1667static const char *alloc_name(u64 flags)
1668{
1669 switch (flags) {
1670 case BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA:
1671 return "mixed";
1672 case BTRFS_BLOCK_GROUP_METADATA:
1673 return "metadata";
1674 case BTRFS_BLOCK_GROUP_DATA:
1675 return "data";
1676 case BTRFS_BLOCK_GROUP_SYSTEM:
1677 return "system";
1678 default:
1679 WARN_ON(1);
1680 return "invalid-combination";
1681 }
1682}
1683
1684/*
1685 * Create a sysfs entry for a space info type at path
1686 * /sys/fs/btrfs/UUID/allocation/TYPE
1687 */
1688int btrfs_sysfs_add_space_info_type(struct btrfs_fs_info *fs_info,
1689 struct btrfs_space_info *space_info)
1690{
1691 int ret;
1692
1693 ret = kobject_init_and_add(kobj: &space_info->kobj, ktype: &space_info_ktype,
1694 parent: fs_info->space_info_kobj, fmt: "%s",
1695 alloc_name(flags: space_info->flags));
1696 if (ret) {
1697 kobject_put(kobj: &space_info->kobj);
1698 return ret;
1699 }
1700
1701 return 0;
1702}
1703
1704void btrfs_sysfs_remove_device(struct btrfs_device *device)
1705{
1706 struct kobject *devices_kobj;
1707
1708 /*
1709 * Seed fs_devices devices_kobj aren't used, fetch kobject from the
1710 * fs_info::fs_devices.
1711 */
1712 devices_kobj = device->fs_info->fs_devices->devices_kobj;
1713 ASSERT(devices_kobj);
1714
1715 if (device->bdev)
1716 sysfs_remove_link(kobj: devices_kobj, bdev_kobj(device->bdev)->name);
1717
1718 if (device->devid_kobj.state_initialized) {
1719 kobject_del(kobj: &device->devid_kobj);
1720 kobject_put(kobj: &device->devid_kobj);
1721 wait_for_completion(&device->kobj_unregister);
1722 }
1723}
1724
1725static ssize_t btrfs_devinfo_in_fs_metadata_show(struct kobject *kobj,
1726 struct kobj_attribute *a,
1727 char *buf)
1728{
1729 int val;
1730 struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1731 devid_kobj);
1732
1733 val = !!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
1734
1735 return sysfs_emit(buf, fmt: "%d\n", val);
1736}
1737BTRFS_ATTR(devid, in_fs_metadata, btrfs_devinfo_in_fs_metadata_show);
1738
1739static ssize_t btrfs_devinfo_missing_show(struct kobject *kobj,
1740 struct kobj_attribute *a, char *buf)
1741{
1742 int val;
1743 struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1744 devid_kobj);
1745
1746 val = !!test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state);
1747
1748 return sysfs_emit(buf, fmt: "%d\n", val);
1749}
1750BTRFS_ATTR(devid, missing, btrfs_devinfo_missing_show);
1751
1752static ssize_t btrfs_devinfo_replace_target_show(struct kobject *kobj,
1753 struct kobj_attribute *a,
1754 char *buf)
1755{
1756 int val;
1757 struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1758 devid_kobj);
1759
1760 val = !!test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state);
1761
1762 return sysfs_emit(buf, fmt: "%d\n", val);
1763}
1764BTRFS_ATTR(devid, replace_target, btrfs_devinfo_replace_target_show);
1765
1766static ssize_t btrfs_devinfo_scrub_speed_max_show(struct kobject *kobj,
1767 struct kobj_attribute *a,
1768 char *buf)
1769{
1770 struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1771 devid_kobj);
1772
1773 return sysfs_emit(buf, fmt: "%llu\n", READ_ONCE(device->scrub_speed_max));
1774}
1775
1776static ssize_t btrfs_devinfo_scrub_speed_max_store(struct kobject *kobj,
1777 struct kobj_attribute *a,
1778 const char *buf, size_t len)
1779{
1780 struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1781 devid_kobj);
1782 char *endptr;
1783 unsigned long long limit;
1784
1785 limit = memparse(ptr: buf, retptr: &endptr);
1786 WRITE_ONCE(device->scrub_speed_max, limit);
1787 return len;
1788}
1789BTRFS_ATTR_RW(devid, scrub_speed_max, btrfs_devinfo_scrub_speed_max_show,
1790 btrfs_devinfo_scrub_speed_max_store);
1791
1792static ssize_t btrfs_devinfo_writeable_show(struct kobject *kobj,
1793 struct kobj_attribute *a, char *buf)
1794{
1795 int val;
1796 struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1797 devid_kobj);
1798
1799 val = !!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
1800
1801 return sysfs_emit(buf, fmt: "%d\n", val);
1802}
1803BTRFS_ATTR(devid, writeable, btrfs_devinfo_writeable_show);
1804
1805static ssize_t btrfs_devinfo_fsid_show(struct kobject *kobj,
1806 struct kobj_attribute *a, char *buf)
1807{
1808 struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1809 devid_kobj);
1810
1811 return sysfs_emit(buf, fmt: "%pU\n", device->fs_devices->fsid);
1812}
1813BTRFS_ATTR(devid, fsid, btrfs_devinfo_fsid_show);
1814
1815static ssize_t btrfs_devinfo_error_stats_show(struct kobject *kobj,
1816 struct kobj_attribute *a, char *buf)
1817{
1818 struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1819 devid_kobj);
1820
1821 if (!device->dev_stats_valid)
1822 return sysfs_emit(buf, fmt: "invalid\n");
1823
1824 /*
1825 * Print all at once so we get a snapshot of all values from the same
1826 * time. Keep them in sync and in order of definition of
1827 * btrfs_dev_stat_values.
1828 */
1829 return sysfs_emit(buf,
1830 fmt: "write_errs %d\n"
1831 "read_errs %d\n"
1832 "flush_errs %d\n"
1833 "corruption_errs %d\n"
1834 "generation_errs %d\n",
1835 btrfs_dev_stat_read(dev: device, index: BTRFS_DEV_STAT_WRITE_ERRS),
1836 btrfs_dev_stat_read(dev: device, index: BTRFS_DEV_STAT_READ_ERRS),
1837 btrfs_dev_stat_read(dev: device, index: BTRFS_DEV_STAT_FLUSH_ERRS),
1838 btrfs_dev_stat_read(dev: device, index: BTRFS_DEV_STAT_CORRUPTION_ERRS),
1839 btrfs_dev_stat_read(dev: device, index: BTRFS_DEV_STAT_GENERATION_ERRS));
1840}
1841BTRFS_ATTR(devid, error_stats, btrfs_devinfo_error_stats_show);
1842
1843/*
1844 * Information about one device.
1845 *
1846 * Path: /sys/fs/btrfs/<uuid>/devinfo/<devid>/
1847 */
1848static struct attribute *devid_attrs[] = {
1849 BTRFS_ATTR_PTR(devid, error_stats),
1850 BTRFS_ATTR_PTR(devid, fsid),
1851 BTRFS_ATTR_PTR(devid, in_fs_metadata),
1852 BTRFS_ATTR_PTR(devid, missing),
1853 BTRFS_ATTR_PTR(devid, replace_target),
1854 BTRFS_ATTR_PTR(devid, scrub_speed_max),
1855 BTRFS_ATTR_PTR(devid, writeable),
1856 NULL
1857};
1858ATTRIBUTE_GROUPS(devid);
1859
1860static void btrfs_release_devid_kobj(struct kobject *kobj)
1861{
1862 struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1863 devid_kobj);
1864
1865 memset(&device->devid_kobj, 0, sizeof(struct kobject));
1866 complete(&device->kobj_unregister);
1867}
1868
1869static const struct kobj_type devid_ktype = {
1870 .sysfs_ops = &kobj_sysfs_ops,
1871 .default_groups = devid_groups,
1872 .release = btrfs_release_devid_kobj,
1873};
1874
1875int btrfs_sysfs_add_device(struct btrfs_device *device)
1876{
1877 int ret;
1878 unsigned int nofs_flag;
1879 struct kobject *devices_kobj;
1880 struct kobject *devinfo_kobj;
1881
1882 /*
1883 * Make sure we use the fs_info::fs_devices to fetch the kobjects even
1884 * for the seed fs_devices
1885 */
1886 devices_kobj = device->fs_info->fs_devices->devices_kobj;
1887 devinfo_kobj = device->fs_info->fs_devices->devinfo_kobj;
1888 ASSERT(devices_kobj);
1889 ASSERT(devinfo_kobj);
1890
1891 nofs_flag = memalloc_nofs_save();
1892
1893 if (device->bdev) {
1894 struct kobject *disk_kobj = bdev_kobj(device->bdev);
1895
1896 ret = sysfs_create_link(kobj: devices_kobj, target: disk_kobj, name: disk_kobj->name);
1897 if (ret) {
1898 btrfs_warn(device->fs_info,
1899 "creating sysfs device link for devid %llu failed: %d",
1900 device->devid, ret);
1901 goto out;
1902 }
1903 }
1904
1905 init_completion(x: &device->kobj_unregister);
1906 ret = kobject_init_and_add(kobj: &device->devid_kobj, ktype: &devid_ktype,
1907 parent: devinfo_kobj, fmt: "%llu", device->devid);
1908 if (ret) {
1909 kobject_put(kobj: &device->devid_kobj);
1910 btrfs_warn(device->fs_info,
1911 "devinfo init for devid %llu failed: %d",
1912 device->devid, ret);
1913 }
1914
1915out:
1916 memalloc_nofs_restore(flags: nofs_flag);
1917 return ret;
1918}
1919
1920static int btrfs_sysfs_add_fs_devices(struct btrfs_fs_devices *fs_devices)
1921{
1922 int ret;
1923 struct btrfs_device *device;
1924 struct btrfs_fs_devices *seed;
1925
1926 list_for_each_entry(device, &fs_devices->devices, dev_list) {
1927 ret = btrfs_sysfs_add_device(device);
1928 if (ret)
1929 goto fail;
1930 }
1931
1932 list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
1933 list_for_each_entry(device, &seed->devices, dev_list) {
1934 ret = btrfs_sysfs_add_device(device);
1935 if (ret)
1936 goto fail;
1937 }
1938 }
1939
1940 return 0;
1941
1942fail:
1943 btrfs_sysfs_remove_fs_devices(fs_devices);
1944 return ret;
1945}
1946
1947void btrfs_kobject_uevent(struct block_device *bdev, enum kobject_action action)
1948{
1949 int ret;
1950
1951 ret = kobject_uevent(kobj: &disk_to_dev(bdev->bd_disk)->kobj, action);
1952 if (ret)
1953 pr_warn("BTRFS: Sending event '%d' to kobject: '%s' (%p): failed\n",
1954 action, kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
1955 &disk_to_dev(bdev->bd_disk)->kobj);
1956}
1957
1958void btrfs_sysfs_update_sprout_fsid(struct btrfs_fs_devices *fs_devices)
1959
1960{
1961 char fsid_buf[BTRFS_UUID_UNPARSED_SIZE];
1962
1963 /*
1964 * Sprouting changes fsid of the mounted filesystem, rename the fsid
1965 * directory
1966 */
1967 snprintf(buf: fsid_buf, BTRFS_UUID_UNPARSED_SIZE, fmt: "%pU", fs_devices->fsid);
1968 if (kobject_rename(&fs_devices->fsid_kobj, new_name: fsid_buf))
1969 btrfs_warn(fs_devices->fs_info,
1970 "sysfs: failed to create fsid for sprout");
1971}
1972
1973void btrfs_sysfs_update_devid(struct btrfs_device *device)
1974{
1975 char tmp[24];
1976
1977 snprintf(buf: tmp, size: sizeof(tmp), fmt: "%llu", device->devid);
1978
1979 if (kobject_rename(&device->devid_kobj, new_name: tmp))
1980 btrfs_warn(device->fs_devices->fs_info,
1981 "sysfs: failed to update devid for %llu",
1982 device->devid);
1983}
1984
1985/* /sys/fs/btrfs/ entry */
1986static struct kset *btrfs_kset;
1987
1988/*
1989 * Creates:
1990 * /sys/fs/btrfs/UUID
1991 *
1992 * Can be called by the device discovery thread.
1993 */
1994int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs)
1995{
1996 int error;
1997
1998 init_completion(x: &fs_devs->kobj_unregister);
1999 fs_devs->fsid_kobj.kset = btrfs_kset;
2000 error = kobject_init_and_add(kobj: &fs_devs->fsid_kobj, ktype: &btrfs_ktype, NULL,
2001 fmt: "%pU", fs_devs->fsid);
2002 if (error) {
2003 kobject_put(kobj: &fs_devs->fsid_kobj);
2004 return error;
2005 }
2006
2007 fs_devs->devices_kobj = kobject_create_and_add(name: "devices",
2008 parent: &fs_devs->fsid_kobj);
2009 if (!fs_devs->devices_kobj) {
2010 btrfs_err(fs_devs->fs_info,
2011 "failed to init sysfs device interface");
2012 btrfs_sysfs_remove_fsid(fs_devs);
2013 return -ENOMEM;
2014 }
2015
2016 fs_devs->devinfo_kobj = kobject_create_and_add(name: "devinfo",
2017 parent: &fs_devs->fsid_kobj);
2018 if (!fs_devs->devinfo_kobj) {
2019 btrfs_err(fs_devs->fs_info,
2020 "failed to init sysfs devinfo kobject");
2021 btrfs_sysfs_remove_fsid(fs_devs);
2022 return -ENOMEM;
2023 }
2024
2025 return 0;
2026}
2027
2028int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info)
2029{
2030 int error;
2031 struct btrfs_fs_devices *fs_devs = fs_info->fs_devices;
2032 struct kobject *fsid_kobj = &fs_devs->fsid_kobj;
2033
2034 error = btrfs_sysfs_add_fs_devices(fs_devices: fs_devs);
2035 if (error)
2036 return error;
2037
2038 error = sysfs_create_files(kobj: fsid_kobj, attr: btrfs_attrs);
2039 if (error) {
2040 btrfs_sysfs_remove_fs_devices(fs_devices: fs_devs);
2041 return error;
2042 }
2043
2044 error = sysfs_create_group(kobj: fsid_kobj,
2045 grp: &btrfs_feature_attr_group);
2046 if (error)
2047 goto failure;
2048
2049#ifdef CONFIG_BTRFS_DEBUG
2050 fs_info->debug_kobj = kobject_create_and_add(name: "debug", parent: fsid_kobj);
2051 if (!fs_info->debug_kobj) {
2052 error = -ENOMEM;
2053 goto failure;
2054 }
2055
2056 error = sysfs_create_files(kobj: fs_info->debug_kobj, attr: btrfs_debug_mount_attrs);
2057 if (error)
2058 goto failure;
2059#endif
2060
2061 /* Discard directory */
2062 fs_info->discard_kobj = kobject_create_and_add(name: "discard", parent: fsid_kobj);
2063 if (!fs_info->discard_kobj) {
2064 error = -ENOMEM;
2065 goto failure;
2066 }
2067
2068 error = sysfs_create_files(kobj: fs_info->discard_kobj, attr: discard_attrs);
2069 if (error)
2070 goto failure;
2071
2072 error = addrm_unknown_feature_attrs(fs_info, add: true);
2073 if (error)
2074 goto failure;
2075
2076 error = sysfs_create_link(kobj: fsid_kobj, target: &fs_info->sb->s_bdi->dev->kobj, name: "bdi");
2077 if (error)
2078 goto failure;
2079
2080 fs_info->space_info_kobj = kobject_create_and_add(name: "allocation",
2081 parent: fsid_kobj);
2082 if (!fs_info->space_info_kobj) {
2083 error = -ENOMEM;
2084 goto failure;
2085 }
2086
2087 error = sysfs_create_files(kobj: fs_info->space_info_kobj, attr: allocation_attrs);
2088 if (error)
2089 goto failure;
2090
2091 return 0;
2092failure:
2093 btrfs_sysfs_remove_mounted(fs_info);
2094 return error;
2095}
2096
2097static ssize_t qgroup_enabled_show(struct kobject *qgroups_kobj,
2098 struct kobj_attribute *a,
2099 char *buf)
2100{
2101 struct btrfs_fs_info *fs_info = to_fs_info(kobj: qgroups_kobj->parent);
2102 bool enabled;
2103
2104 spin_lock(lock: &fs_info->qgroup_lock);
2105 enabled = fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON;
2106 spin_unlock(lock: &fs_info->qgroup_lock);
2107
2108 return sysfs_emit(buf, fmt: "%d\n", enabled);
2109}
2110BTRFS_ATTR(qgroups, enabled, qgroup_enabled_show);
2111
2112static ssize_t qgroup_mode_show(struct kobject *qgroups_kobj,
2113 struct kobj_attribute *a,
2114 char *buf)
2115{
2116 struct btrfs_fs_info *fs_info = to_fs_info(kobj: qgroups_kobj->parent);
2117 ssize_t ret = 0;
2118
2119 spin_lock(lock: &fs_info->qgroup_lock);
2120 ASSERT(btrfs_qgroup_enabled(fs_info));
2121 switch (btrfs_qgroup_mode(fs_info)) {
2122 case BTRFS_QGROUP_MODE_FULL:
2123 ret = sysfs_emit(buf, fmt: "qgroup\n");
2124 break;
2125 case BTRFS_QGROUP_MODE_SIMPLE:
2126 ret = sysfs_emit(buf, fmt: "squota\n");
2127 break;
2128 default:
2129 btrfs_warn(fs_info, "unexpected qgroup mode %d\n",
2130 btrfs_qgroup_mode(fs_info));
2131 break;
2132 }
2133 spin_unlock(lock: &fs_info->qgroup_lock);
2134
2135 return ret;
2136}
2137BTRFS_ATTR(qgroups, mode, qgroup_mode_show);
2138
2139static ssize_t qgroup_inconsistent_show(struct kobject *qgroups_kobj,
2140 struct kobj_attribute *a,
2141 char *buf)
2142{
2143 struct btrfs_fs_info *fs_info = to_fs_info(kobj: qgroups_kobj->parent);
2144 bool inconsistent;
2145
2146 spin_lock(lock: &fs_info->qgroup_lock);
2147 inconsistent = (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT);
2148 spin_unlock(lock: &fs_info->qgroup_lock);
2149
2150 return sysfs_emit(buf, fmt: "%d\n", inconsistent);
2151}
2152BTRFS_ATTR(qgroups, inconsistent, qgroup_inconsistent_show);
2153
2154static ssize_t qgroup_drop_subtree_thres_show(struct kobject *qgroups_kobj,
2155 struct kobj_attribute *a,
2156 char *buf)
2157{
2158 struct btrfs_fs_info *fs_info = to_fs_info(kobj: qgroups_kobj->parent);
2159 u8 result;
2160
2161 spin_lock(lock: &fs_info->qgroup_lock);
2162 result = fs_info->qgroup_drop_subtree_thres;
2163 spin_unlock(lock: &fs_info->qgroup_lock);
2164
2165 return sysfs_emit(buf, fmt: "%d\n", result);
2166}
2167
2168static ssize_t qgroup_drop_subtree_thres_store(struct kobject *qgroups_kobj,
2169 struct kobj_attribute *a,
2170 const char *buf, size_t len)
2171{
2172 struct btrfs_fs_info *fs_info = to_fs_info(kobj: qgroups_kobj->parent);
2173 u8 new_thres;
2174 int ret;
2175
2176 ret = kstrtou8(s: buf, base: 10, res: &new_thres);
2177 if (ret)
2178 return -EINVAL;
2179
2180 if (new_thres > BTRFS_MAX_LEVEL)
2181 return -EINVAL;
2182
2183 spin_lock(lock: &fs_info->qgroup_lock);
2184 fs_info->qgroup_drop_subtree_thres = new_thres;
2185 spin_unlock(lock: &fs_info->qgroup_lock);
2186
2187 return len;
2188}
2189BTRFS_ATTR_RW(qgroups, drop_subtree_threshold, qgroup_drop_subtree_thres_show,
2190 qgroup_drop_subtree_thres_store);
2191
2192/*
2193 * Qgroups global info
2194 *
2195 * Path: /sys/fs/btrfs/<uuid>/qgroups/
2196 */
2197static struct attribute *qgroups_attrs[] = {
2198 BTRFS_ATTR_PTR(qgroups, enabled),
2199 BTRFS_ATTR_PTR(qgroups, inconsistent),
2200 BTRFS_ATTR_PTR(qgroups, drop_subtree_threshold),
2201 BTRFS_ATTR_PTR(qgroups, mode),
2202 NULL
2203};
2204ATTRIBUTE_GROUPS(qgroups);
2205
2206static void qgroups_release(struct kobject *kobj)
2207{
2208 kfree(objp: kobj);
2209}
2210
2211static const struct kobj_type qgroups_ktype = {
2212 .sysfs_ops = &kobj_sysfs_ops,
2213 .default_groups = qgroups_groups,
2214 .release = qgroups_release,
2215};
2216
2217static inline struct btrfs_fs_info *qgroup_kobj_to_fs_info(struct kobject *kobj)
2218{
2219 return to_fs_info(kobj: kobj->parent->parent);
2220}
2221
2222#define QGROUP_ATTR(_member, _show_name) \
2223static ssize_t btrfs_qgroup_show_##_member(struct kobject *qgroup_kobj, \
2224 struct kobj_attribute *a, \
2225 char *buf) \
2226{ \
2227 struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj); \
2228 struct btrfs_qgroup *qgroup = container_of(qgroup_kobj, \
2229 struct btrfs_qgroup, kobj); \
2230 return btrfs_show_u64(&qgroup->_member, &fs_info->qgroup_lock, buf); \
2231} \
2232BTRFS_ATTR(qgroup, _show_name, btrfs_qgroup_show_##_member)
2233
2234#define QGROUP_RSV_ATTR(_name, _type) \
2235static ssize_t btrfs_qgroup_rsv_show_##_name(struct kobject *qgroup_kobj, \
2236 struct kobj_attribute *a, \
2237 char *buf) \
2238{ \
2239 struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj); \
2240 struct btrfs_qgroup *qgroup = container_of(qgroup_kobj, \
2241 struct btrfs_qgroup, kobj); \
2242 return btrfs_show_u64(&qgroup->rsv.values[_type], \
2243 &fs_info->qgroup_lock, buf); \
2244} \
2245BTRFS_ATTR(qgroup, rsv_##_name, btrfs_qgroup_rsv_show_##_name)
2246
2247QGROUP_ATTR(rfer, referenced);
2248QGROUP_ATTR(excl, exclusive);
2249QGROUP_ATTR(max_rfer, max_referenced);
2250QGROUP_ATTR(max_excl, max_exclusive);
2251QGROUP_ATTR(lim_flags, limit_flags);
2252QGROUP_RSV_ATTR(data, BTRFS_QGROUP_RSV_DATA);
2253QGROUP_RSV_ATTR(meta_pertrans, BTRFS_QGROUP_RSV_META_PERTRANS);
2254QGROUP_RSV_ATTR(meta_prealloc, BTRFS_QGROUP_RSV_META_PREALLOC);
2255
2256/*
2257 * Qgroup information.
2258 *
2259 * Path: /sys/fs/btrfs/<uuid>/qgroups/<level>_<qgroupid>/
2260 */
2261static struct attribute *qgroup_attrs[] = {
2262 BTRFS_ATTR_PTR(qgroup, referenced),
2263 BTRFS_ATTR_PTR(qgroup, exclusive),
2264 BTRFS_ATTR_PTR(qgroup, max_referenced),
2265 BTRFS_ATTR_PTR(qgroup, max_exclusive),
2266 BTRFS_ATTR_PTR(qgroup, limit_flags),
2267 BTRFS_ATTR_PTR(qgroup, rsv_data),
2268 BTRFS_ATTR_PTR(qgroup, rsv_meta_pertrans),
2269 BTRFS_ATTR_PTR(qgroup, rsv_meta_prealloc),
2270 NULL
2271};
2272ATTRIBUTE_GROUPS(qgroup);
2273
2274static void qgroup_release(struct kobject *kobj)
2275{
2276 struct btrfs_qgroup *qgroup = container_of(kobj, struct btrfs_qgroup, kobj);
2277
2278 memset(&qgroup->kobj, 0, sizeof(*kobj));
2279}
2280
2281static const struct kobj_type qgroup_ktype = {
2282 .sysfs_ops = &kobj_sysfs_ops,
2283 .release = qgroup_release,
2284 .default_groups = qgroup_groups,
2285};
2286
2287int btrfs_sysfs_add_one_qgroup(struct btrfs_fs_info *fs_info,
2288 struct btrfs_qgroup *qgroup)
2289{
2290 struct kobject *qgroups_kobj = fs_info->qgroups_kobj;
2291 int ret;
2292
2293 if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
2294 return 0;
2295 if (qgroup->kobj.state_initialized)
2296 return 0;
2297 if (!qgroups_kobj)
2298 return -EINVAL;
2299
2300 ret = kobject_init_and_add(kobj: &qgroup->kobj, ktype: &qgroup_ktype, parent: qgroups_kobj,
2301 fmt: "%hu_%llu", btrfs_qgroup_level(qgroupid: qgroup->qgroupid),
2302 btrfs_qgroup_subvolid(qgroupid: qgroup->qgroupid));
2303 if (ret < 0)
2304 kobject_put(kobj: &qgroup->kobj);
2305
2306 return ret;
2307}
2308
2309void btrfs_sysfs_del_qgroups(struct btrfs_fs_info *fs_info)
2310{
2311 struct btrfs_qgroup *qgroup;
2312 struct btrfs_qgroup *next;
2313
2314 if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
2315 return;
2316
2317 rbtree_postorder_for_each_entry_safe(qgroup, next,
2318 &fs_info->qgroup_tree, node)
2319 btrfs_sysfs_del_one_qgroup(fs_info, qgroup);
2320 if (fs_info->qgroups_kobj) {
2321 kobject_del(kobj: fs_info->qgroups_kobj);
2322 kobject_put(kobj: fs_info->qgroups_kobj);
2323 fs_info->qgroups_kobj = NULL;
2324 }
2325}
2326
2327/* Called when qgroups get initialized, thus there is no need for locking */
2328int btrfs_sysfs_add_qgroups(struct btrfs_fs_info *fs_info)
2329{
2330 struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
2331 struct btrfs_qgroup *qgroup;
2332 struct btrfs_qgroup *next;
2333 int ret = 0;
2334
2335 if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
2336 return 0;
2337
2338 ASSERT(fsid_kobj);
2339 if (fs_info->qgroups_kobj)
2340 return 0;
2341
2342 fs_info->qgroups_kobj = kzalloc(size: sizeof(struct kobject), GFP_KERNEL);
2343 if (!fs_info->qgroups_kobj)
2344 return -ENOMEM;
2345
2346 ret = kobject_init_and_add(kobj: fs_info->qgroups_kobj, ktype: &qgroups_ktype,
2347 parent: fsid_kobj, fmt: "qgroups");
2348 if (ret < 0)
2349 goto out;
2350
2351 rbtree_postorder_for_each_entry_safe(qgroup, next,
2352 &fs_info->qgroup_tree, node) {
2353 ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
2354 if (ret < 0)
2355 goto out;
2356 }
2357
2358out:
2359 if (ret < 0)
2360 btrfs_sysfs_del_qgroups(fs_info);
2361 return ret;
2362}
2363
2364void btrfs_sysfs_del_one_qgroup(struct btrfs_fs_info *fs_info,
2365 struct btrfs_qgroup *qgroup)
2366{
2367 if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
2368 return;
2369
2370 if (qgroup->kobj.state_initialized) {
2371 kobject_del(kobj: &qgroup->kobj);
2372 kobject_put(kobj: &qgroup->kobj);
2373 }
2374}
2375
2376/*
2377 * Change per-fs features in /sys/fs/btrfs/UUID/features to match current
2378 * values in superblock. Call after any changes to incompat/compat_ro flags
2379 */
2380void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info)
2381{
2382 struct kobject *fsid_kobj;
2383 int ret;
2384
2385 if (!fs_info)
2386 return;
2387
2388 fsid_kobj = &fs_info->fs_devices->fsid_kobj;
2389 if (!fsid_kobj->state_initialized)
2390 return;
2391
2392 ret = sysfs_update_group(kobj: fsid_kobj, grp: &btrfs_feature_attr_group);
2393 if (ret < 0)
2394 btrfs_warn(fs_info,
2395 "failed to update /sys/fs/btrfs/%pU/features: %d",
2396 fs_info->fs_devices->fsid, ret);
2397}
2398
2399int __init btrfs_init_sysfs(void)
2400{
2401 int ret;
2402
2403 btrfs_kset = kset_create_and_add(name: "btrfs", NULL, parent_kobj: fs_kobj);
2404 if (!btrfs_kset)
2405 return -ENOMEM;
2406
2407 init_feature_attrs();
2408 ret = sysfs_create_group(kobj: &btrfs_kset->kobj, grp: &btrfs_feature_attr_group);
2409 if (ret)
2410 goto out2;
2411 ret = sysfs_merge_group(kobj: &btrfs_kset->kobj,
2412 grp: &btrfs_static_feature_attr_group);
2413 if (ret)
2414 goto out_remove_group;
2415
2416#ifdef CONFIG_BTRFS_DEBUG
2417 ret = sysfs_create_group(kobj: &btrfs_kset->kobj, grp: &btrfs_debug_feature_attr_group);
2418 if (ret) {
2419 sysfs_unmerge_group(kobj: &btrfs_kset->kobj,
2420 grp: &btrfs_static_feature_attr_group);
2421 goto out_remove_group;
2422 }
2423#endif
2424
2425 return 0;
2426
2427out_remove_group:
2428 sysfs_remove_group(kobj: &btrfs_kset->kobj, grp: &btrfs_feature_attr_group);
2429out2:
2430 kset_unregister(kset: btrfs_kset);
2431
2432 return ret;
2433}
2434
2435void __cold btrfs_exit_sysfs(void)
2436{
2437 sysfs_unmerge_group(kobj: &btrfs_kset->kobj,
2438 grp: &btrfs_static_feature_attr_group);
2439 sysfs_remove_group(kobj: &btrfs_kset->kobj, grp: &btrfs_feature_attr_group);
2440#ifdef CONFIG_BTRFS_DEBUG
2441 sysfs_remove_group(kobj: &btrfs_kset->kobj, grp: &btrfs_debug_feature_attr_group);
2442#endif
2443 kset_unregister(kset: btrfs_kset);
2444}
2445

source code of linux/fs/btrfs/sysfs.c