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btrfs: add and use helpers for reading and writing fs_info->generation
[thirdparty/linux.git] / fs / btrfs / sysfs.c
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
49 struct 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 */
56 struct 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) \
84 static 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
101 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj);
102 static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj);
103 static struct kobject *get_btrfs_kobj(struct kobject *kobj);
104
105 static 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
110 static struct kobj_attribute *attr_to_btrfs_attr(struct attribute *attr)
111 {
112 return container_of(attr, struct kobj_attribute, attr);
113 }
114
115 static 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
121 static 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
133 static 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
145 static 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
176 static ssize_t btrfs_feature_attr_show(struct kobject *kobj,
177 struct kobj_attribute *a, char *buf)
178 {
179 int val = 0;
180 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
181 struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
182 if (fs_info) {
183 u64 features = get_features(fs_info, 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
192 static ssize_t btrfs_feature_attr_store(struct kobject *kobj,
193 struct kobj_attribute *a,
194 const char *buf, size_t count)
195 {
196 struct btrfs_fs_info *fs_info;
197 struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
198 u64 features, set, clear;
199 unsigned long val;
200 int ret;
201
202 fs_info = to_fs_info(kobj);
203 if (!fs_info)
204 return -EPERM;
205
206 if (sb_rdonly(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
260 static umode_t btrfs_feature_visible(struct kobject *kobj,
261 struct attribute *attr, int unused)
262 {
263 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
264 umode_t mode = attr->mode;
265
266 if (fs_info) {
267 struct btrfs_feature_attr *fa;
268 u64 features;
269
270 fa = attr_to_btrfs_feature_attr(attr);
271 features = get_features(fs_info, fa->feature_set);
272
273 if (can_modify_feature(fa))
274 mode |= S_IWUSR;
275 else if (!(features & fa->feature_bit))
276 mode = 0;
277 }
278
279 return mode;
280 }
281
282 BTRFS_FEAT_ATTR_INCOMPAT(default_subvol, DEFAULT_SUBVOL);
283 BTRFS_FEAT_ATTR_INCOMPAT(mixed_groups, MIXED_GROUPS);
284 BTRFS_FEAT_ATTR_INCOMPAT(compress_lzo, COMPRESS_LZO);
285 BTRFS_FEAT_ATTR_INCOMPAT(compress_zstd, COMPRESS_ZSTD);
286 BTRFS_FEAT_ATTR_INCOMPAT(extended_iref, EXTENDED_IREF);
287 BTRFS_FEAT_ATTR_INCOMPAT(raid56, RAID56);
288 BTRFS_FEAT_ATTR_INCOMPAT(skinny_metadata, SKINNY_METADATA);
289 BTRFS_FEAT_ATTR_INCOMPAT(no_holes, NO_HOLES);
290 BTRFS_FEAT_ATTR_INCOMPAT(metadata_uuid, METADATA_UUID);
291 BTRFS_FEAT_ATTR_COMPAT_RO(free_space_tree, FREE_SPACE_TREE);
292 BTRFS_FEAT_ATTR_COMPAT_RO(block_group_tree, BLOCK_GROUP_TREE);
293 BTRFS_FEAT_ATTR_INCOMPAT(raid1c34, RAID1C34);
294 BTRFS_FEAT_ATTR_INCOMPAT(simple_quota, SIMPLE_QUOTA);
295 #ifdef CONFIG_BLK_DEV_ZONED
296 BTRFS_FEAT_ATTR_INCOMPAT(zoned, ZONED);
297 #endif
298 #ifdef CONFIG_BTRFS_DEBUG
299 /* Remove once support for extent tree v2 is feature complete */
300 BTRFS_FEAT_ATTR_INCOMPAT(extent_tree_v2, EXTENT_TREE_V2);
301 /* Remove once support for raid stripe tree is feature complete. */
302 BTRFS_FEAT_ATTR_INCOMPAT(raid_stripe_tree, RAID_STRIPE_TREE);
303 #endif
304 #ifdef CONFIG_FS_VERITY
305 BTRFS_FEAT_ATTR_COMPAT_RO(verity, VERITY);
306 #endif
307
308 /*
309 * Features which depend on feature bits and may differ between each fs.
310 *
311 * /sys/fs/btrfs/features - all available features implemented by this version
312 * /sys/fs/btrfs/UUID/features - features of the fs which are enabled or
313 * can be changed on a mounted filesystem.
314 */
315 static struct attribute *btrfs_supported_feature_attrs[] = {
316 BTRFS_FEAT_ATTR_PTR(default_subvol),
317 BTRFS_FEAT_ATTR_PTR(mixed_groups),
318 BTRFS_FEAT_ATTR_PTR(compress_lzo),
319 BTRFS_FEAT_ATTR_PTR(compress_zstd),
320 BTRFS_FEAT_ATTR_PTR(extended_iref),
321 BTRFS_FEAT_ATTR_PTR(raid56),
322 BTRFS_FEAT_ATTR_PTR(skinny_metadata),
323 BTRFS_FEAT_ATTR_PTR(no_holes),
324 BTRFS_FEAT_ATTR_PTR(metadata_uuid),
325 BTRFS_FEAT_ATTR_PTR(free_space_tree),
326 BTRFS_FEAT_ATTR_PTR(raid1c34),
327 BTRFS_FEAT_ATTR_PTR(block_group_tree),
328 BTRFS_FEAT_ATTR_PTR(simple_quota),
329 #ifdef CONFIG_BLK_DEV_ZONED
330 BTRFS_FEAT_ATTR_PTR(zoned),
331 #endif
332 #ifdef CONFIG_BTRFS_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
342 static const struct attribute_group btrfs_feature_attr_group = {
343 .name = "features",
344 .is_visible = btrfs_feature_visible,
345 .attrs = btrfs_supported_feature_attrs,
346 };
347
348 static ssize_t rmdir_subvol_show(struct kobject *kobj,
349 struct kobj_attribute *ka, char *buf)
350 {
351 return sysfs_emit(buf, "0\n");
352 }
353 BTRFS_ATTR(static_feature, rmdir_subvol, rmdir_subvol_show);
354
355 static ssize_t supported_checksums_show(struct kobject *kobj,
356 struct kobj_attribute *a, char *buf)
357 {
358 ssize_t ret = 0;
359 int i;
360
361 for (i = 0; i < btrfs_get_num_csums(); i++) {
362 /*
363 * This "trick" only works as long as 'enum btrfs_csum_type' has
364 * no holes in it
365 */
366 ret += sysfs_emit_at(buf, ret, "%s%s", (i == 0 ? "" : " "),
367 btrfs_super_csum_name(i));
368
369 }
370
371 ret += sysfs_emit_at(buf, ret, "\n");
372 return ret;
373 }
374 BTRFS_ATTR(static_feature, supported_checksums, supported_checksums_show);
375
376 static ssize_t send_stream_version_show(struct kobject *kobj,
377 struct kobj_attribute *ka, char *buf)
378 {
379 return sysfs_emit(buf, "%d\n", BTRFS_SEND_STREAM_VERSION);
380 }
381 BTRFS_ATTR(static_feature, send_stream_version, send_stream_version_show);
382
383 static const char *rescue_opts[] = {
384 "usebackuproot",
385 "nologreplay",
386 "ignorebadroots",
387 "ignoredatacsums",
388 "all",
389 };
390
391 static 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, ret, "%s%s", (i ? " " : ""), rescue_opts[i]);
400 ret += sysfs_emit_at(buf, ret, "\n");
401 return ret;
402 }
403 BTRFS_ATTR(static_feature, supported_rescue_options,
404 supported_rescue_options_show);
405
406 static 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, ret, "%u ", SZ_4K);
415 ret += sysfs_emit_at(buf, ret, "%lu\n", PAGE_SIZE);
416
417 return ret;
418 }
419 BTRFS_ATTR(static_feature, supported_sectorsizes,
420 supported_sectorsizes_show);
421
422 static ssize_t acl_show(struct kobject *kobj, struct kobj_attribute *a, char *buf)
423 {
424 return sysfs_emit(buf, "%d\n", !!IS_ENABLED(CONFIG_BTRFS_FS_POSIX_ACL));
425 }
426 BTRFS_ATTR(static_feature, acl, acl_show);
427
428 /*
429 * Features which only depend on kernel version.
430 *
431 * These are listed in /sys/fs/btrfs/features along with
432 * btrfs_supported_feature_attrs.
433 */
434 static struct attribute *btrfs_supported_static_feature_attrs[] = {
435 BTRFS_ATTR_PTR(static_feature, acl),
436 BTRFS_ATTR_PTR(static_feature, rmdir_subvol),
437 BTRFS_ATTR_PTR(static_feature, supported_checksums),
438 BTRFS_ATTR_PTR(static_feature, send_stream_version),
439 BTRFS_ATTR_PTR(static_feature, supported_rescue_options),
440 BTRFS_ATTR_PTR(static_feature, supported_sectorsizes),
441 NULL
442 };
443
444 static const struct attribute_group btrfs_static_feature_attr_group = {
445 .name = "features",
446 .attrs = btrfs_supported_static_feature_attrs,
447 };
448
449 /*
450 * Discard statistics and tunables
451 */
452 #define discard_to_fs_info(_kobj) to_fs_info(get_btrfs_kobj(_kobj))
453
454 static ssize_t btrfs_discardable_bytes_show(struct kobject *kobj,
455 struct kobj_attribute *a,
456 char *buf)
457 {
458 struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
459
460 return sysfs_emit(buf, "%lld\n",
461 atomic64_read(&fs_info->discard_ctl.discardable_bytes));
462 }
463 BTRFS_ATTR(discard, discardable_bytes, btrfs_discardable_bytes_show);
464
465 static ssize_t btrfs_discardable_extents_show(struct kobject *kobj,
466 struct kobj_attribute *a,
467 char *buf)
468 {
469 struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
470
471 return sysfs_emit(buf, "%d\n",
472 atomic_read(&fs_info->discard_ctl.discardable_extents));
473 }
474 BTRFS_ATTR(discard, discardable_extents, btrfs_discardable_extents_show);
475
476 static ssize_t btrfs_discard_bitmap_bytes_show(struct kobject *kobj,
477 struct kobj_attribute *a,
478 char *buf)
479 {
480 struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
481
482 return sysfs_emit(buf, "%llu\n",
483 fs_info->discard_ctl.discard_bitmap_bytes);
484 }
485 BTRFS_ATTR(discard, discard_bitmap_bytes, btrfs_discard_bitmap_bytes_show);
486
487 static ssize_t btrfs_discard_bytes_saved_show(struct kobject *kobj,
488 struct kobj_attribute *a,
489 char *buf)
490 {
491 struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
492
493 return sysfs_emit(buf, "%lld\n",
494 atomic64_read(&fs_info->discard_ctl.discard_bytes_saved));
495 }
496 BTRFS_ATTR(discard, discard_bytes_saved, btrfs_discard_bytes_saved_show);
497
498 static ssize_t btrfs_discard_extent_bytes_show(struct kobject *kobj,
499 struct kobj_attribute *a,
500 char *buf)
501 {
502 struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
503
504 return sysfs_emit(buf, "%llu\n",
505 fs_info->discard_ctl.discard_extent_bytes);
506 }
507 BTRFS_ATTR(discard, discard_extent_bytes, btrfs_discard_extent_bytes_show);
508
509 static ssize_t btrfs_discard_iops_limit_show(struct kobject *kobj,
510 struct kobj_attribute *a,
511 char *buf)
512 {
513 struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
514
515 return sysfs_emit(buf, "%u\n",
516 READ_ONCE(fs_info->discard_ctl.iops_limit));
517 }
518
519 static ssize_t btrfs_discard_iops_limit_store(struct kobject *kobj,
520 struct kobj_attribute *a,
521 const char *buf, size_t len)
522 {
523 struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
524 struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
525 u32 iops_limit;
526 int ret;
527
528 ret = kstrtou32(buf, 10, &iops_limit);
529 if (ret)
530 return -EINVAL;
531
532 WRITE_ONCE(discard_ctl->iops_limit, iops_limit);
533 btrfs_discard_calc_delay(discard_ctl);
534 btrfs_discard_schedule_work(discard_ctl, true);
535 return len;
536 }
537 BTRFS_ATTR_RW(discard, iops_limit, btrfs_discard_iops_limit_show,
538 btrfs_discard_iops_limit_store);
539
540 static ssize_t btrfs_discard_kbps_limit_show(struct kobject *kobj,
541 struct kobj_attribute *a,
542 char *buf)
543 {
544 struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
545
546 return sysfs_emit(buf, "%u\n",
547 READ_ONCE(fs_info->discard_ctl.kbps_limit));
548 }
549
550 static ssize_t btrfs_discard_kbps_limit_store(struct kobject *kobj,
551 struct kobj_attribute *a,
552 const char *buf, size_t len)
553 {
554 struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
555 struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
556 u32 kbps_limit;
557 int ret;
558
559 ret = kstrtou32(buf, 10, &kbps_limit);
560 if (ret)
561 return -EINVAL;
562
563 WRITE_ONCE(discard_ctl->kbps_limit, kbps_limit);
564 btrfs_discard_schedule_work(discard_ctl, true);
565 return len;
566 }
567 BTRFS_ATTR_RW(discard, kbps_limit, btrfs_discard_kbps_limit_show,
568 btrfs_discard_kbps_limit_store);
569
570 static ssize_t btrfs_discard_max_discard_size_show(struct kobject *kobj,
571 struct kobj_attribute *a,
572 char *buf)
573 {
574 struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
575
576 return sysfs_emit(buf, "%llu\n",
577 READ_ONCE(fs_info->discard_ctl.max_discard_size));
578 }
579
580 static ssize_t btrfs_discard_max_discard_size_store(struct kobject *kobj,
581 struct kobj_attribute *a,
582 const char *buf, size_t len)
583 {
584 struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
585 struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
586 u64 max_discard_size;
587 int ret;
588
589 ret = kstrtou64(buf, 10, &max_discard_size);
590 if (ret)
591 return -EINVAL;
592
593 WRITE_ONCE(discard_ctl->max_discard_size, max_discard_size);
594
595 return len;
596 }
597 BTRFS_ATTR_RW(discard, max_discard_size, btrfs_discard_max_discard_size_show,
598 btrfs_discard_max_discard_size_store);
599
600 /*
601 * Per-filesystem stats for discard (when mounted with discard=async).
602 *
603 * Path: /sys/fs/btrfs/<uuid>/discard/
604 */
605 static const struct attribute *discard_attrs[] = {
606 BTRFS_ATTR_PTR(discard, discardable_bytes),
607 BTRFS_ATTR_PTR(discard, discardable_extents),
608 BTRFS_ATTR_PTR(discard, discard_bitmap_bytes),
609 BTRFS_ATTR_PTR(discard, discard_bytes_saved),
610 BTRFS_ATTR_PTR(discard, discard_extent_bytes),
611 BTRFS_ATTR_PTR(discard, iops_limit),
612 BTRFS_ATTR_PTR(discard, kbps_limit),
613 BTRFS_ATTR_PTR(discard, max_discard_size),
614 NULL,
615 };
616
617 #ifdef CONFIG_BTRFS_DEBUG
618
619 /*
620 * Per-filesystem runtime debugging exported via sysfs.
621 *
622 * Path: /sys/fs/btrfs/UUID/debug/
623 */
624 static const struct attribute *btrfs_debug_mount_attrs[] = {
625 NULL,
626 };
627
628 /*
629 * Runtime debugging exported via sysfs, applies to all mounted filesystems.
630 *
631 * Path: /sys/fs/btrfs/debug
632 */
633 static struct attribute *btrfs_debug_feature_attrs[] = {
634 NULL
635 };
636
637 static const struct attribute_group btrfs_debug_feature_attr_group = {
638 .name = "debug",
639 .attrs = btrfs_debug_feature_attrs,
640 };
641
642 #endif
643
644 static ssize_t btrfs_show_u64(u64 *value_ptr, spinlock_t *lock, char *buf)
645 {
646 u64 val;
647 if (lock)
648 spin_lock(lock);
649 val = *value_ptr;
650 if (lock)
651 spin_unlock(lock);
652 return sysfs_emit(buf, "%llu\n", val);
653 }
654
655 static ssize_t global_rsv_size_show(struct kobject *kobj,
656 struct kobj_attribute *ka, char *buf)
657 {
658 struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
659 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
660 return btrfs_show_u64(&block_rsv->size, &block_rsv->lock, buf);
661 }
662 BTRFS_ATTR(allocation, global_rsv_size, global_rsv_size_show);
663
664 static ssize_t global_rsv_reserved_show(struct kobject *kobj,
665 struct kobj_attribute *a, char *buf)
666 {
667 struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
668 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
669 return btrfs_show_u64(&block_rsv->reserved, &block_rsv->lock, buf);
670 }
671 BTRFS_ATTR(allocation, global_rsv_reserved, global_rsv_reserved_show);
672
673 #define to_space_info(_kobj) container_of(_kobj, struct btrfs_space_info, kobj)
674 #define to_raid_kobj(_kobj) container_of(_kobj, struct raid_kobject, kobj)
675
676 static ssize_t raid_bytes_show(struct kobject *kobj,
677 struct kobj_attribute *attr, char *buf);
678 BTRFS_ATTR(raid, total_bytes, raid_bytes_show);
679 BTRFS_ATTR(raid, used_bytes, raid_bytes_show);
680
681 static ssize_t raid_bytes_show(struct kobject *kobj,
682 struct kobj_attribute *attr, char *buf)
683
684 {
685 struct btrfs_space_info *sinfo = to_space_info(kobj->parent);
686 struct btrfs_block_group *block_group;
687 int index = btrfs_bg_flags_to_raid_index(to_raid_kobj(kobj)->flags);
688 u64 val = 0;
689
690 down_read(&sinfo->groups_sem);
691 list_for_each_entry(block_group, &sinfo->block_groups[index], list) {
692 if (&attr->attr == BTRFS_ATTR_PTR(raid, total_bytes))
693 val += block_group->length;
694 else
695 val += block_group->used;
696 }
697 up_read(&sinfo->groups_sem);
698 return sysfs_emit(buf, "%llu\n", val);
699 }
700
701 /*
702 * Allocation information about block group profiles.
703 *
704 * Path: /sys/fs/btrfs/<uuid>/allocation/<bg-type>/<bg-profile>/
705 */
706 static struct attribute *raid_attrs[] = {
707 BTRFS_ATTR_PTR(raid, total_bytes),
708 BTRFS_ATTR_PTR(raid, used_bytes),
709 NULL
710 };
711 ATTRIBUTE_GROUPS(raid);
712
713 static void release_raid_kobj(struct kobject *kobj)
714 {
715 kfree(to_raid_kobj(kobj));
716 }
717
718 static const struct kobj_type btrfs_raid_ktype = {
719 .sysfs_ops = &kobj_sysfs_ops,
720 .release = release_raid_kobj,
721 .default_groups = raid_groups,
722 };
723
724 #define SPACE_INFO_ATTR(field) \
725 static ssize_t btrfs_space_info_show_##field(struct kobject *kobj, \
726 struct kobj_attribute *a, \
727 char *buf) \
728 { \
729 struct btrfs_space_info *sinfo = to_space_info(kobj); \
730 return btrfs_show_u64(&sinfo->field, &sinfo->lock, buf); \
731 } \
732 BTRFS_ATTR(space_info, field, btrfs_space_info_show_##field)
733
734 static ssize_t btrfs_chunk_size_show(struct kobject *kobj,
735 struct kobj_attribute *a, char *buf)
736 {
737 struct btrfs_space_info *sinfo = to_space_info(kobj);
738
739 return sysfs_emit(buf, "%llu\n", READ_ONCE(sinfo->chunk_size));
740 }
741
742 /*
743 * Store new chunk size in space info. Can be called on a read-only filesystem.
744 *
745 * If the new chunk size value is larger than 10% of free space it is reduced
746 * to match that limit. Alignment must be to 256M and the system chunk size
747 * cannot be set.
748 */
749 static ssize_t btrfs_chunk_size_store(struct kobject *kobj,
750 struct kobj_attribute *a,
751 const char *buf, size_t len)
752 {
753 struct btrfs_space_info *space_info = to_space_info(kobj);
754 struct btrfs_fs_info *fs_info = to_fs_info(get_btrfs_kobj(kobj));
755 char *retptr;
756 u64 val;
757
758 if (!capable(CAP_SYS_ADMIN))
759 return -EPERM;
760
761 if (!fs_info->fs_devices)
762 return -EINVAL;
763
764 if (btrfs_is_zoned(fs_info))
765 return -EINVAL;
766
767 /* System block type must not be changed. */
768 if (space_info->flags & BTRFS_BLOCK_GROUP_SYSTEM)
769 return -EPERM;
770
771 val = memparse(buf, &retptr);
772 /* There could be trailing '\n', also catch any typos after the value */
773 retptr = skip_spaces(retptr);
774 if (*retptr != 0 || val == 0)
775 return -EINVAL;
776
777 val = min(val, BTRFS_MAX_DATA_CHUNK_SIZE);
778
779 /* Limit stripe size to 10% of available space. */
780 val = min(mult_perc(fs_info->fs_devices->total_rw_bytes, 10), val);
781
782 /* Must be multiple of 256M. */
783 val &= ~((u64)SZ_256M - 1);
784
785 /* Must be at least 256M. */
786 if (val < SZ_256M)
787 return -EINVAL;
788
789 btrfs_update_space_info_chunk_size(space_info, val);
790
791 return len;
792 }
793
794 static ssize_t btrfs_size_classes_show(struct kobject *kobj,
795 struct kobj_attribute *a, char *buf)
796 {
797 struct btrfs_space_info *sinfo = to_space_info(kobj);
798 struct btrfs_block_group *bg;
799 u32 none = 0;
800 u32 small = 0;
801 u32 medium = 0;
802 u32 large = 0;
803
804 for (int i = 0; i < BTRFS_NR_RAID_TYPES; ++i) {
805 down_read(&sinfo->groups_sem);
806 list_for_each_entry(bg, &sinfo->block_groups[i], list) {
807 if (!btrfs_block_group_should_use_size_class(bg))
808 continue;
809 switch (bg->size_class) {
810 case BTRFS_BG_SZ_NONE:
811 none++;
812 break;
813 case BTRFS_BG_SZ_SMALL:
814 small++;
815 break;
816 case BTRFS_BG_SZ_MEDIUM:
817 medium++;
818 break;
819 case BTRFS_BG_SZ_LARGE:
820 large++;
821 break;
822 }
823 }
824 up_read(&sinfo->groups_sem);
825 }
826 return sysfs_emit(buf, "none %u\n"
827 "small %u\n"
828 "medium %u\n"
829 "large %u\n",
830 none, small, medium, large);
831 }
832
833 #ifdef CONFIG_BTRFS_DEBUG
834 /*
835 * Request chunk allocation with current chunk size.
836 */
837 static ssize_t btrfs_force_chunk_alloc_store(struct kobject *kobj,
838 struct kobj_attribute *a,
839 const char *buf, size_t len)
840 {
841 struct btrfs_space_info *space_info = to_space_info(kobj);
842 struct btrfs_fs_info *fs_info = to_fs_info(get_btrfs_kobj(kobj));
843 struct btrfs_trans_handle *trans;
844 bool val;
845 int ret;
846
847 if (!capable(CAP_SYS_ADMIN))
848 return -EPERM;
849
850 if (sb_rdonly(fs_info->sb))
851 return -EROFS;
852
853 ret = kstrtobool(buf, &val);
854 if (ret)
855 return ret;
856
857 if (!val)
858 return -EINVAL;
859
860 /*
861 * This is unsafe to be called from sysfs context and may cause
862 * unexpected problems.
863 */
864 trans = btrfs_start_transaction(fs_info->tree_root, 0);
865 if (IS_ERR(trans))
866 return PTR_ERR(trans);
867 ret = btrfs_force_chunk_alloc(trans, space_info->flags);
868 btrfs_end_transaction(trans);
869
870 if (ret == 1)
871 return len;
872
873 return -ENOSPC;
874 }
875 BTRFS_ATTR_W(space_info, force_chunk_alloc, btrfs_force_chunk_alloc_store);
876
877 #endif
878
879 SPACE_INFO_ATTR(flags);
880 SPACE_INFO_ATTR(total_bytes);
881 SPACE_INFO_ATTR(bytes_used);
882 SPACE_INFO_ATTR(bytes_pinned);
883 SPACE_INFO_ATTR(bytes_reserved);
884 SPACE_INFO_ATTR(bytes_may_use);
885 SPACE_INFO_ATTR(bytes_readonly);
886 SPACE_INFO_ATTR(bytes_zone_unusable);
887 SPACE_INFO_ATTR(disk_used);
888 SPACE_INFO_ATTR(disk_total);
889 BTRFS_ATTR_RW(space_info, chunk_size, btrfs_chunk_size_show, btrfs_chunk_size_store);
890 BTRFS_ATTR(space_info, size_classes, btrfs_size_classes_show);
891
892 static ssize_t btrfs_sinfo_bg_reclaim_threshold_show(struct kobject *kobj,
893 struct kobj_attribute *a,
894 char *buf)
895 {
896 struct btrfs_space_info *space_info = to_space_info(kobj);
897
898 return sysfs_emit(buf, "%d\n", READ_ONCE(space_info->bg_reclaim_threshold));
899 }
900
901 static ssize_t btrfs_sinfo_bg_reclaim_threshold_store(struct kobject *kobj,
902 struct kobj_attribute *a,
903 const char *buf, size_t len)
904 {
905 struct btrfs_space_info *space_info = to_space_info(kobj);
906 int thresh;
907 int ret;
908
909 ret = kstrtoint(buf, 10, &thresh);
910 if (ret)
911 return ret;
912
913 if (thresh < 0 || thresh > 100)
914 return -EINVAL;
915
916 WRITE_ONCE(space_info->bg_reclaim_threshold, thresh);
917
918 return len;
919 }
920
921 BTRFS_ATTR_RW(space_info, bg_reclaim_threshold,
922 btrfs_sinfo_bg_reclaim_threshold_show,
923 btrfs_sinfo_bg_reclaim_threshold_store);
924
925 /*
926 * Allocation information about block group types.
927 *
928 * Path: /sys/fs/btrfs/<uuid>/allocation/<bg-type>/
929 */
930 static struct attribute *space_info_attrs[] = {
931 BTRFS_ATTR_PTR(space_info, flags),
932 BTRFS_ATTR_PTR(space_info, total_bytes),
933 BTRFS_ATTR_PTR(space_info, bytes_used),
934 BTRFS_ATTR_PTR(space_info, bytes_pinned),
935 BTRFS_ATTR_PTR(space_info, bytes_reserved),
936 BTRFS_ATTR_PTR(space_info, bytes_may_use),
937 BTRFS_ATTR_PTR(space_info, bytes_readonly),
938 BTRFS_ATTR_PTR(space_info, bytes_zone_unusable),
939 BTRFS_ATTR_PTR(space_info, disk_used),
940 BTRFS_ATTR_PTR(space_info, disk_total),
941 BTRFS_ATTR_PTR(space_info, bg_reclaim_threshold),
942 BTRFS_ATTR_PTR(space_info, chunk_size),
943 BTRFS_ATTR_PTR(space_info, size_classes),
944 #ifdef CONFIG_BTRFS_DEBUG
945 BTRFS_ATTR_PTR(space_info, force_chunk_alloc),
946 #endif
947 NULL,
948 };
949 ATTRIBUTE_GROUPS(space_info);
950
951 static void space_info_release(struct kobject *kobj)
952 {
953 struct btrfs_space_info *sinfo = to_space_info(kobj);
954 kfree(sinfo);
955 }
956
957 static const struct kobj_type space_info_ktype = {
958 .sysfs_ops = &kobj_sysfs_ops,
959 .release = space_info_release,
960 .default_groups = space_info_groups,
961 };
962
963 /*
964 * Allocation information about block groups.
965 *
966 * Path: /sys/fs/btrfs/<uuid>/allocation/
967 */
968 static const struct attribute *allocation_attrs[] = {
969 BTRFS_ATTR_PTR(allocation, global_rsv_reserved),
970 BTRFS_ATTR_PTR(allocation, global_rsv_size),
971 NULL,
972 };
973
974 static ssize_t btrfs_label_show(struct kobject *kobj,
975 struct kobj_attribute *a, char *buf)
976 {
977 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
978 char *label = fs_info->super_copy->label;
979 ssize_t ret;
980
981 spin_lock(&fs_info->super_lock);
982 ret = sysfs_emit(buf, label[0] ? "%s\n" : "%s", label);
983 spin_unlock(&fs_info->super_lock);
984
985 return ret;
986 }
987
988 static ssize_t btrfs_label_store(struct kobject *kobj,
989 struct kobj_attribute *a,
990 const char *buf, size_t len)
991 {
992 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
993 size_t p_len;
994
995 if (!fs_info)
996 return -EPERM;
997
998 if (sb_rdonly(fs_info->sb))
999 return -EROFS;
1000
1001 /*
1002 * p_len is the len until the first occurrence of either
1003 * '\n' or '\0'
1004 */
1005 p_len = strcspn(buf, "\n");
1006
1007 if (p_len >= BTRFS_LABEL_SIZE)
1008 return -EINVAL;
1009
1010 spin_lock(&fs_info->super_lock);
1011 memset(fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE);
1012 memcpy(fs_info->super_copy->label, buf, p_len);
1013 spin_unlock(&fs_info->super_lock);
1014
1015 /*
1016 * We don't want to do full transaction commit from inside sysfs
1017 */
1018 set_bit(BTRFS_FS_NEED_TRANS_COMMIT, &fs_info->flags);
1019 wake_up_process(fs_info->transaction_kthread);
1020
1021 return len;
1022 }
1023 BTRFS_ATTR_RW(, label, btrfs_label_show, btrfs_label_store);
1024
1025 static ssize_t btrfs_nodesize_show(struct kobject *kobj,
1026 struct kobj_attribute *a, char *buf)
1027 {
1028 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1029
1030 return sysfs_emit(buf, "%u\n", fs_info->super_copy->nodesize);
1031 }
1032
1033 BTRFS_ATTR(, nodesize, btrfs_nodesize_show);
1034
1035 static ssize_t btrfs_sectorsize_show(struct kobject *kobj,
1036 struct kobj_attribute *a, char *buf)
1037 {
1038 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1039
1040 return sysfs_emit(buf, "%u\n", fs_info->super_copy->sectorsize);
1041 }
1042
1043 BTRFS_ATTR(, sectorsize, btrfs_sectorsize_show);
1044
1045 static ssize_t btrfs_commit_stats_show(struct kobject *kobj,
1046 struct kobj_attribute *a, char *buf)
1047 {
1048 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1049
1050 return sysfs_emit(buf,
1051 "commits %llu\n"
1052 "last_commit_ms %llu\n"
1053 "max_commit_ms %llu\n"
1054 "total_commit_ms %llu\n",
1055 fs_info->commit_stats.commit_count,
1056 div_u64(fs_info->commit_stats.last_commit_dur, NSEC_PER_MSEC),
1057 div_u64(fs_info->commit_stats.max_commit_dur, NSEC_PER_MSEC),
1058 div_u64(fs_info->commit_stats.total_commit_dur, NSEC_PER_MSEC));
1059 }
1060
1061 static ssize_t btrfs_commit_stats_store(struct kobject *kobj,
1062 struct kobj_attribute *a,
1063 const char *buf, size_t len)
1064 {
1065 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1066 unsigned long val;
1067 int ret;
1068
1069 if (!fs_info)
1070 return -EPERM;
1071
1072 if (!capable(CAP_SYS_RESOURCE))
1073 return -EPERM;
1074
1075 ret = kstrtoul(buf, 10, &val);
1076 if (ret)
1077 return ret;
1078 if (val)
1079 return -EINVAL;
1080
1081 WRITE_ONCE(fs_info->commit_stats.max_commit_dur, 0);
1082
1083 return len;
1084 }
1085 BTRFS_ATTR_RW(, commit_stats, btrfs_commit_stats_show, btrfs_commit_stats_store);
1086
1087 static ssize_t btrfs_clone_alignment_show(struct kobject *kobj,
1088 struct kobj_attribute *a, char *buf)
1089 {
1090 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1091
1092 return sysfs_emit(buf, "%u\n", fs_info->super_copy->sectorsize);
1093 }
1094
1095 BTRFS_ATTR(, clone_alignment, btrfs_clone_alignment_show);
1096
1097 static ssize_t quota_override_show(struct kobject *kobj,
1098 struct kobj_attribute *a, char *buf)
1099 {
1100 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1101 int quota_override;
1102
1103 quota_override = test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
1104 return sysfs_emit(buf, "%d\n", quota_override);
1105 }
1106
1107 static ssize_t quota_override_store(struct kobject *kobj,
1108 struct kobj_attribute *a,
1109 const char *buf, size_t len)
1110 {
1111 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1112 unsigned long knob;
1113 int err;
1114
1115 if (!fs_info)
1116 return -EPERM;
1117
1118 if (!capable(CAP_SYS_RESOURCE))
1119 return -EPERM;
1120
1121 err = kstrtoul(buf, 10, &knob);
1122 if (err)
1123 return err;
1124 if (knob > 1)
1125 return -EINVAL;
1126
1127 if (knob)
1128 set_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
1129 else
1130 clear_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
1131
1132 return len;
1133 }
1134
1135 BTRFS_ATTR_RW(, quota_override, quota_override_show, quota_override_store);
1136
1137 static ssize_t btrfs_metadata_uuid_show(struct kobject *kobj,
1138 struct kobj_attribute *a, char *buf)
1139 {
1140 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1141
1142 return sysfs_emit(buf, "%pU\n", fs_info->fs_devices->metadata_uuid);
1143 }
1144
1145 BTRFS_ATTR(, metadata_uuid, btrfs_metadata_uuid_show);
1146
1147 static ssize_t btrfs_checksum_show(struct kobject *kobj,
1148 struct kobj_attribute *a, char *buf)
1149 {
1150 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1151 u16 csum_type = btrfs_super_csum_type(fs_info->super_copy);
1152
1153 return sysfs_emit(buf, "%s (%s)\n",
1154 btrfs_super_csum_name(csum_type),
1155 crypto_shash_driver_name(fs_info->csum_shash));
1156 }
1157
1158 BTRFS_ATTR(, checksum, btrfs_checksum_show);
1159
1160 static ssize_t btrfs_exclusive_operation_show(struct kobject *kobj,
1161 struct kobj_attribute *a, char *buf)
1162 {
1163 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1164 const char *str;
1165
1166 switch (READ_ONCE(fs_info->exclusive_operation)) {
1167 case BTRFS_EXCLOP_NONE:
1168 str = "none\n";
1169 break;
1170 case BTRFS_EXCLOP_BALANCE:
1171 str = "balance\n";
1172 break;
1173 case BTRFS_EXCLOP_BALANCE_PAUSED:
1174 str = "balance paused\n";
1175 break;
1176 case BTRFS_EXCLOP_DEV_ADD:
1177 str = "device add\n";
1178 break;
1179 case BTRFS_EXCLOP_DEV_REMOVE:
1180 str = "device remove\n";
1181 break;
1182 case BTRFS_EXCLOP_DEV_REPLACE:
1183 str = "device replace\n";
1184 break;
1185 case BTRFS_EXCLOP_RESIZE:
1186 str = "resize\n";
1187 break;
1188 case BTRFS_EXCLOP_SWAP_ACTIVATE:
1189 str = "swap activate\n";
1190 break;
1191 default:
1192 str = "UNKNOWN\n";
1193 break;
1194 }
1195 return sysfs_emit(buf, "%s", str);
1196 }
1197 BTRFS_ATTR(, exclusive_operation, btrfs_exclusive_operation_show);
1198
1199 static ssize_t btrfs_generation_show(struct kobject *kobj,
1200 struct kobj_attribute *a, char *buf)
1201 {
1202 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1203
1204 return sysfs_emit(buf, "%llu\n", btrfs_get_fs_generation(fs_info));
1205 }
1206 BTRFS_ATTR(, generation, btrfs_generation_show);
1207
1208 static const char * const btrfs_read_policy_name[] = { "pid" };
1209
1210 static ssize_t btrfs_read_policy_show(struct kobject *kobj,
1211 struct kobj_attribute *a, char *buf)
1212 {
1213 struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
1214 ssize_t ret = 0;
1215 int i;
1216
1217 for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
1218 if (fs_devices->read_policy == i)
1219 ret += sysfs_emit_at(buf, ret, "%s[%s]",
1220 (ret == 0 ? "" : " "),
1221 btrfs_read_policy_name[i]);
1222 else
1223 ret += sysfs_emit_at(buf, ret, "%s%s",
1224 (ret == 0 ? "" : " "),
1225 btrfs_read_policy_name[i]);
1226 }
1227
1228 ret += sysfs_emit_at(buf, ret, "\n");
1229
1230 return ret;
1231 }
1232
1233 static ssize_t btrfs_read_policy_store(struct kobject *kobj,
1234 struct kobj_attribute *a,
1235 const char *buf, size_t len)
1236 {
1237 struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
1238 int i;
1239
1240 for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
1241 if (sysfs_streq(buf, btrfs_read_policy_name[i])) {
1242 if (i != fs_devices->read_policy) {
1243 fs_devices->read_policy = i;
1244 btrfs_info(fs_devices->fs_info,
1245 "read policy set to '%s'",
1246 btrfs_read_policy_name[i]);
1247 }
1248 return len;
1249 }
1250 }
1251
1252 return -EINVAL;
1253 }
1254 BTRFS_ATTR_RW(, read_policy, btrfs_read_policy_show, btrfs_read_policy_store);
1255
1256 static ssize_t btrfs_bg_reclaim_threshold_show(struct kobject *kobj,
1257 struct kobj_attribute *a,
1258 char *buf)
1259 {
1260 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1261
1262 return sysfs_emit(buf, "%d\n", READ_ONCE(fs_info->bg_reclaim_threshold));
1263 }
1264
1265 static ssize_t btrfs_bg_reclaim_threshold_store(struct kobject *kobj,
1266 struct kobj_attribute *a,
1267 const char *buf, size_t len)
1268 {
1269 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1270 int thresh;
1271 int ret;
1272
1273 ret = kstrtoint(buf, 10, &thresh);
1274 if (ret)
1275 return ret;
1276
1277 #ifdef CONFIG_BTRFS_DEBUG
1278 if (thresh != 0 && (thresh > 100))
1279 return -EINVAL;
1280 #else
1281 if (thresh != 0 && (thresh <= 50 || thresh > 100))
1282 return -EINVAL;
1283 #endif
1284
1285 WRITE_ONCE(fs_info->bg_reclaim_threshold, thresh);
1286
1287 return len;
1288 }
1289 BTRFS_ATTR_RW(, bg_reclaim_threshold, btrfs_bg_reclaim_threshold_show,
1290 btrfs_bg_reclaim_threshold_store);
1291
1292 /*
1293 * Per-filesystem information and stats.
1294 *
1295 * Path: /sys/fs/btrfs/<uuid>/
1296 */
1297 static const struct attribute *btrfs_attrs[] = {
1298 BTRFS_ATTR_PTR(, label),
1299 BTRFS_ATTR_PTR(, nodesize),
1300 BTRFS_ATTR_PTR(, sectorsize),
1301 BTRFS_ATTR_PTR(, clone_alignment),
1302 BTRFS_ATTR_PTR(, quota_override),
1303 BTRFS_ATTR_PTR(, metadata_uuid),
1304 BTRFS_ATTR_PTR(, checksum),
1305 BTRFS_ATTR_PTR(, exclusive_operation),
1306 BTRFS_ATTR_PTR(, generation),
1307 BTRFS_ATTR_PTR(, read_policy),
1308 BTRFS_ATTR_PTR(, bg_reclaim_threshold),
1309 BTRFS_ATTR_PTR(, commit_stats),
1310 NULL,
1311 };
1312
1313 static void btrfs_release_fsid_kobj(struct kobject *kobj)
1314 {
1315 struct btrfs_fs_devices *fs_devs = to_fs_devs(kobj);
1316
1317 memset(&fs_devs->fsid_kobj, 0, sizeof(struct kobject));
1318 complete(&fs_devs->kobj_unregister);
1319 }
1320
1321 static const struct kobj_type btrfs_ktype = {
1322 .sysfs_ops = &kobj_sysfs_ops,
1323 .release = btrfs_release_fsid_kobj,
1324 };
1325
1326 static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj)
1327 {
1328 if (kobj->ktype != &btrfs_ktype)
1329 return NULL;
1330 return container_of(kobj, struct btrfs_fs_devices, fsid_kobj);
1331 }
1332
1333 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)
1334 {
1335 if (kobj->ktype != &btrfs_ktype)
1336 return NULL;
1337 return to_fs_devs(kobj)->fs_info;
1338 }
1339
1340 static struct kobject *get_btrfs_kobj(struct kobject *kobj)
1341 {
1342 while (kobj) {
1343 if (kobj->ktype == &btrfs_ktype)
1344 return kobj;
1345 kobj = kobj->parent;
1346 }
1347 return NULL;
1348 }
1349
1350 #define NUM_FEATURE_BITS 64
1351 #define BTRFS_FEATURE_NAME_MAX 13
1352 static char btrfs_unknown_feature_names[FEAT_MAX][NUM_FEATURE_BITS][BTRFS_FEATURE_NAME_MAX];
1353 static struct btrfs_feature_attr btrfs_feature_attrs[FEAT_MAX][NUM_FEATURE_BITS];
1354
1355 static_assert(ARRAY_SIZE(btrfs_unknown_feature_names) ==
1356 ARRAY_SIZE(btrfs_feature_attrs));
1357 static_assert(ARRAY_SIZE(btrfs_unknown_feature_names[0]) ==
1358 ARRAY_SIZE(btrfs_feature_attrs[0]));
1359
1360 static const u64 supported_feature_masks[FEAT_MAX] = {
1361 [FEAT_COMPAT] = BTRFS_FEATURE_COMPAT_SUPP,
1362 [FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP,
1363 [FEAT_INCOMPAT] = BTRFS_FEATURE_INCOMPAT_SUPP,
1364 };
1365
1366 static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add)
1367 {
1368 int set;
1369
1370 for (set = 0; set < FEAT_MAX; set++) {
1371 int i;
1372 struct attribute *attrs[2];
1373 struct attribute_group agroup = {
1374 .name = "features",
1375 .attrs = attrs,
1376 };
1377 u64 features = get_features(fs_info, set);
1378 features &= ~supported_feature_masks[set];
1379
1380 if (!features)
1381 continue;
1382
1383 attrs[1] = NULL;
1384 for (i = 0; i < NUM_FEATURE_BITS; i++) {
1385 struct btrfs_feature_attr *fa;
1386
1387 if (!(features & (1ULL << i)))
1388 continue;
1389
1390 fa = &btrfs_feature_attrs[set][i];
1391 attrs[0] = &fa->kobj_attr.attr;
1392 if (add) {
1393 int ret;
1394 ret = sysfs_merge_group(&fs_info->fs_devices->fsid_kobj,
1395 &agroup);
1396 if (ret)
1397 return ret;
1398 } else
1399 sysfs_unmerge_group(&fs_info->fs_devices->fsid_kobj,
1400 &agroup);
1401 }
1402
1403 }
1404 return 0;
1405 }
1406
1407 static void __btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1408 {
1409 if (fs_devs->devinfo_kobj) {
1410 kobject_del(fs_devs->devinfo_kobj);
1411 kobject_put(fs_devs->devinfo_kobj);
1412 fs_devs->devinfo_kobj = NULL;
1413 }
1414
1415 if (fs_devs->devices_kobj) {
1416 kobject_del(fs_devs->devices_kobj);
1417 kobject_put(fs_devs->devices_kobj);
1418 fs_devs->devices_kobj = NULL;
1419 }
1420
1421 if (fs_devs->fsid_kobj.state_initialized) {
1422 kobject_del(&fs_devs->fsid_kobj);
1423 kobject_put(&fs_devs->fsid_kobj);
1424 wait_for_completion(&fs_devs->kobj_unregister);
1425 }
1426 }
1427
1428 /* when fs_devs is NULL it will remove all fsid kobject */
1429 void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1430 {
1431 struct list_head *fs_uuids = btrfs_get_fs_uuids();
1432
1433 if (fs_devs) {
1434 __btrfs_sysfs_remove_fsid(fs_devs);
1435 return;
1436 }
1437
1438 list_for_each_entry(fs_devs, fs_uuids, fs_list) {
1439 __btrfs_sysfs_remove_fsid(fs_devs);
1440 }
1441 }
1442
1443 static void btrfs_sysfs_remove_fs_devices(struct btrfs_fs_devices *fs_devices)
1444 {
1445 struct btrfs_device *device;
1446 struct btrfs_fs_devices *seed;
1447
1448 list_for_each_entry(device, &fs_devices->devices, dev_list)
1449 btrfs_sysfs_remove_device(device);
1450
1451 list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
1452 list_for_each_entry(device, &seed->devices, dev_list)
1453 btrfs_sysfs_remove_device(device);
1454 }
1455 }
1456
1457 void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info)
1458 {
1459 struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
1460
1461 sysfs_remove_link(fsid_kobj, "bdi");
1462
1463 if (fs_info->space_info_kobj) {
1464 sysfs_remove_files(fs_info->space_info_kobj, allocation_attrs);
1465 kobject_del(fs_info->space_info_kobj);
1466 kobject_put(fs_info->space_info_kobj);
1467 }
1468 if (fs_info->discard_kobj) {
1469 sysfs_remove_files(fs_info->discard_kobj, discard_attrs);
1470 kobject_del(fs_info->discard_kobj);
1471 kobject_put(fs_info->discard_kobj);
1472 }
1473 #ifdef CONFIG_BTRFS_DEBUG
1474 if (fs_info->debug_kobj) {
1475 sysfs_remove_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
1476 kobject_del(fs_info->debug_kobj);
1477 kobject_put(fs_info->debug_kobj);
1478 }
1479 #endif
1480 addrm_unknown_feature_attrs(fs_info, false);
1481 sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
1482 sysfs_remove_files(fsid_kobj, btrfs_attrs);
1483 btrfs_sysfs_remove_fs_devices(fs_info->fs_devices);
1484 }
1485
1486 static const char * const btrfs_feature_set_names[FEAT_MAX] = {
1487 [FEAT_COMPAT] = "compat",
1488 [FEAT_COMPAT_RO] = "compat_ro",
1489 [FEAT_INCOMPAT] = "incompat",
1490 };
1491
1492 const char *btrfs_feature_set_name(enum btrfs_feature_set set)
1493 {
1494 return btrfs_feature_set_names[set];
1495 }
1496
1497 char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags)
1498 {
1499 size_t bufsize = 4096; /* safe max, 64 names * 64 bytes */
1500 int len = 0;
1501 int i;
1502 char *str;
1503
1504 str = kmalloc(bufsize, GFP_KERNEL);
1505 if (!str)
1506 return str;
1507
1508 for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1509 const char *name;
1510
1511 if (!(flags & (1ULL << i)))
1512 continue;
1513
1514 name = btrfs_feature_attrs[set][i].kobj_attr.attr.name;
1515 len += scnprintf(str + len, bufsize - len, "%s%s",
1516 len ? "," : "", name);
1517 }
1518
1519 return str;
1520 }
1521
1522 static void init_feature_attrs(void)
1523 {
1524 struct btrfs_feature_attr *fa;
1525 int set, i;
1526
1527 memset(btrfs_feature_attrs, 0, sizeof(btrfs_feature_attrs));
1528 memset(btrfs_unknown_feature_names, 0,
1529 sizeof(btrfs_unknown_feature_names));
1530
1531 for (i = 0; btrfs_supported_feature_attrs[i]; i++) {
1532 struct btrfs_feature_attr *sfa;
1533 struct attribute *a = btrfs_supported_feature_attrs[i];
1534 int bit;
1535 sfa = attr_to_btrfs_feature_attr(a);
1536 bit = ilog2(sfa->feature_bit);
1537 fa = &btrfs_feature_attrs[sfa->feature_set][bit];
1538
1539 fa->kobj_attr.attr.name = sfa->kobj_attr.attr.name;
1540 }
1541
1542 for (set = 0; set < FEAT_MAX; set++) {
1543 for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1544 char *name = btrfs_unknown_feature_names[set][i];
1545 fa = &btrfs_feature_attrs[set][i];
1546
1547 if (fa->kobj_attr.attr.name)
1548 continue;
1549
1550 snprintf(name, BTRFS_FEATURE_NAME_MAX, "%s:%u",
1551 btrfs_feature_set_names[set], i);
1552
1553 fa->kobj_attr.attr.name = name;
1554 fa->kobj_attr.attr.mode = S_IRUGO;
1555 fa->feature_set = set;
1556 fa->feature_bit = 1ULL << i;
1557 }
1558 }
1559 }
1560
1561 /*
1562 * Create a sysfs entry for a given block group type at path
1563 * /sys/fs/btrfs/UUID/allocation/data/TYPE
1564 */
1565 void btrfs_sysfs_add_block_group_type(struct btrfs_block_group *cache)
1566 {
1567 struct btrfs_fs_info *fs_info = cache->fs_info;
1568 struct btrfs_space_info *space_info = cache->space_info;
1569 struct raid_kobject *rkobj;
1570 const int index = btrfs_bg_flags_to_raid_index(cache->flags);
1571 unsigned int nofs_flag;
1572 int ret;
1573
1574 /*
1575 * Setup a NOFS context because kobject_add(), deep in its call chain,
1576 * does GFP_KERNEL allocations, and we are often called in a context
1577 * where if reclaim is triggered we can deadlock (we are either holding
1578 * a transaction handle or some lock required for a transaction
1579 * commit).
1580 */
1581 nofs_flag = memalloc_nofs_save();
1582
1583 rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS);
1584 if (!rkobj) {
1585 memalloc_nofs_restore(nofs_flag);
1586 btrfs_warn(cache->fs_info,
1587 "couldn't alloc memory for raid level kobject");
1588 return;
1589 }
1590
1591 rkobj->flags = cache->flags;
1592 kobject_init(&rkobj->kobj, &btrfs_raid_ktype);
1593
1594 /*
1595 * We call this either on mount, or if we've created a block group for a
1596 * new index type while running (i.e. when restriping). The running
1597 * case is tricky because we could race with other threads, so we need
1598 * to have this check to make sure we didn't already init the kobject.
1599 *
1600 * We don't have to protect on the free side because it only happens on
1601 * unmount.
1602 */
1603 spin_lock(&space_info->lock);
1604 if (space_info->block_group_kobjs[index]) {
1605 spin_unlock(&space_info->lock);
1606 kobject_put(&rkobj->kobj);
1607 return;
1608 } else {
1609 space_info->block_group_kobjs[index] = &rkobj->kobj;
1610 }
1611 spin_unlock(&space_info->lock);
1612
1613 ret = kobject_add(&rkobj->kobj, &space_info->kobj, "%s",
1614 btrfs_bg_type_to_raid_name(rkobj->flags));
1615 memalloc_nofs_restore(nofs_flag);
1616 if (ret) {
1617 spin_lock(&space_info->lock);
1618 space_info->block_group_kobjs[index] = NULL;
1619 spin_unlock(&space_info->lock);
1620 kobject_put(&rkobj->kobj);
1621 btrfs_warn(fs_info,
1622 "failed to add kobject for block cache, ignoring");
1623 return;
1624 }
1625 }
1626
1627 /*
1628 * Remove sysfs directories for all block group types of a given space info and
1629 * the space info as well
1630 */
1631 void btrfs_sysfs_remove_space_info(struct btrfs_space_info *space_info)
1632 {
1633 int i;
1634
1635 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
1636 struct kobject *kobj;
1637
1638 kobj = space_info->block_group_kobjs[i];
1639 space_info->block_group_kobjs[i] = NULL;
1640 if (kobj) {
1641 kobject_del(kobj);
1642 kobject_put(kobj);
1643 }
1644 }
1645 kobject_del(&space_info->kobj);
1646 kobject_put(&space_info->kobj);
1647 }
1648
1649 static const char *alloc_name(u64 flags)
1650 {
1651 switch (flags) {
1652 case BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA:
1653 return "mixed";
1654 case BTRFS_BLOCK_GROUP_METADATA:
1655 return "metadata";
1656 case BTRFS_BLOCK_GROUP_DATA:
1657 return "data";
1658 case BTRFS_BLOCK_GROUP_SYSTEM:
1659 return "system";
1660 default:
1661 WARN_ON(1);
1662 return "invalid-combination";
1663 }
1664 }
1665
1666 /*
1667 * Create a sysfs entry for a space info type at path
1668 * /sys/fs/btrfs/UUID/allocation/TYPE
1669 */
1670 int btrfs_sysfs_add_space_info_type(struct btrfs_fs_info *fs_info,
1671 struct btrfs_space_info *space_info)
1672 {
1673 int ret;
1674
1675 ret = kobject_init_and_add(&space_info->kobj, &space_info_ktype,
1676 fs_info->space_info_kobj, "%s",
1677 alloc_name(space_info->flags));
1678 if (ret) {
1679 kobject_put(&space_info->kobj);
1680 return ret;
1681 }
1682
1683 return 0;
1684 }
1685
1686 void btrfs_sysfs_remove_device(struct btrfs_device *device)
1687 {
1688 struct kobject *devices_kobj;
1689
1690 /*
1691 * Seed fs_devices devices_kobj aren't used, fetch kobject from the
1692 * fs_info::fs_devices.
1693 */
1694 devices_kobj = device->fs_info->fs_devices->devices_kobj;
1695 ASSERT(devices_kobj);
1696
1697 if (device->bdev)
1698 sysfs_remove_link(devices_kobj, bdev_kobj(device->bdev)->name);
1699
1700 if (device->devid_kobj.state_initialized) {
1701 kobject_del(&device->devid_kobj);
1702 kobject_put(&device->devid_kobj);
1703 wait_for_completion(&device->kobj_unregister);
1704 }
1705 }
1706
1707 static ssize_t btrfs_devinfo_in_fs_metadata_show(struct kobject *kobj,
1708 struct kobj_attribute *a,
1709 char *buf)
1710 {
1711 int val;
1712 struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1713 devid_kobj);
1714
1715 val = !!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
1716
1717 return sysfs_emit(buf, "%d\n", val);
1718 }
1719 BTRFS_ATTR(devid, in_fs_metadata, btrfs_devinfo_in_fs_metadata_show);
1720
1721 static ssize_t btrfs_devinfo_missing_show(struct kobject *kobj,
1722 struct kobj_attribute *a, char *buf)
1723 {
1724 int val;
1725 struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1726 devid_kobj);
1727
1728 val = !!test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state);
1729
1730 return sysfs_emit(buf, "%d\n", val);
1731 }
1732 BTRFS_ATTR(devid, missing, btrfs_devinfo_missing_show);
1733
1734 static ssize_t btrfs_devinfo_replace_target_show(struct kobject *kobj,
1735 struct kobj_attribute *a,
1736 char *buf)
1737 {
1738 int val;
1739 struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1740 devid_kobj);
1741
1742 val = !!test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state);
1743
1744 return sysfs_emit(buf, "%d\n", val);
1745 }
1746 BTRFS_ATTR(devid, replace_target, btrfs_devinfo_replace_target_show);
1747
1748 static ssize_t btrfs_devinfo_scrub_speed_max_show(struct kobject *kobj,
1749 struct kobj_attribute *a,
1750 char *buf)
1751 {
1752 struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1753 devid_kobj);
1754
1755 return sysfs_emit(buf, "%llu\n", READ_ONCE(device->scrub_speed_max));
1756 }
1757
1758 static ssize_t btrfs_devinfo_scrub_speed_max_store(struct kobject *kobj,
1759 struct kobj_attribute *a,
1760 const char *buf, size_t len)
1761 {
1762 struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1763 devid_kobj);
1764 char *endptr;
1765 unsigned long long limit;
1766
1767 limit = memparse(buf, &endptr);
1768 WRITE_ONCE(device->scrub_speed_max, limit);
1769 return len;
1770 }
1771 BTRFS_ATTR_RW(devid, scrub_speed_max, btrfs_devinfo_scrub_speed_max_show,
1772 btrfs_devinfo_scrub_speed_max_store);
1773
1774 static ssize_t btrfs_devinfo_writeable_show(struct kobject *kobj,
1775 struct kobj_attribute *a, char *buf)
1776 {
1777 int val;
1778 struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1779 devid_kobj);
1780
1781 val = !!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
1782
1783 return sysfs_emit(buf, "%d\n", val);
1784 }
1785 BTRFS_ATTR(devid, writeable, btrfs_devinfo_writeable_show);
1786
1787 static ssize_t btrfs_devinfo_fsid_show(struct kobject *kobj,
1788 struct kobj_attribute *a, char *buf)
1789 {
1790 struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1791 devid_kobj);
1792
1793 return sysfs_emit(buf, "%pU\n", device->fs_devices->fsid);
1794 }
1795 BTRFS_ATTR(devid, fsid, btrfs_devinfo_fsid_show);
1796
1797 static ssize_t btrfs_devinfo_error_stats_show(struct kobject *kobj,
1798 struct kobj_attribute *a, char *buf)
1799 {
1800 struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1801 devid_kobj);
1802
1803 if (!device->dev_stats_valid)
1804 return sysfs_emit(buf, "invalid\n");
1805
1806 /*
1807 * Print all at once so we get a snapshot of all values from the same
1808 * time. Keep them in sync and in order of definition of
1809 * btrfs_dev_stat_values.
1810 */
1811 return sysfs_emit(buf,
1812 "write_errs %d\n"
1813 "read_errs %d\n"
1814 "flush_errs %d\n"
1815 "corruption_errs %d\n"
1816 "generation_errs %d\n",
1817 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_WRITE_ERRS),
1818 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_READ_ERRS),
1819 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_FLUSH_ERRS),
1820 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_CORRUPTION_ERRS),
1821 btrfs_dev_stat_read(device, BTRFS_DEV_STAT_GENERATION_ERRS));
1822 }
1823 BTRFS_ATTR(devid, error_stats, btrfs_devinfo_error_stats_show);
1824
1825 /*
1826 * Information about one device.
1827 *
1828 * Path: /sys/fs/btrfs/<uuid>/devinfo/<devid>/
1829 */
1830 static struct attribute *devid_attrs[] = {
1831 BTRFS_ATTR_PTR(devid, error_stats),
1832 BTRFS_ATTR_PTR(devid, fsid),
1833 BTRFS_ATTR_PTR(devid, in_fs_metadata),
1834 BTRFS_ATTR_PTR(devid, missing),
1835 BTRFS_ATTR_PTR(devid, replace_target),
1836 BTRFS_ATTR_PTR(devid, scrub_speed_max),
1837 BTRFS_ATTR_PTR(devid, writeable),
1838 NULL
1839 };
1840 ATTRIBUTE_GROUPS(devid);
1841
1842 static void btrfs_release_devid_kobj(struct kobject *kobj)
1843 {
1844 struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1845 devid_kobj);
1846
1847 memset(&device->devid_kobj, 0, sizeof(struct kobject));
1848 complete(&device->kobj_unregister);
1849 }
1850
1851 static const struct kobj_type devid_ktype = {
1852 .sysfs_ops = &kobj_sysfs_ops,
1853 .default_groups = devid_groups,
1854 .release = btrfs_release_devid_kobj,
1855 };
1856
1857 int btrfs_sysfs_add_device(struct btrfs_device *device)
1858 {
1859 int ret;
1860 unsigned int nofs_flag;
1861 struct kobject *devices_kobj;
1862 struct kobject *devinfo_kobj;
1863
1864 /*
1865 * Make sure we use the fs_info::fs_devices to fetch the kobjects even
1866 * for the seed fs_devices
1867 */
1868 devices_kobj = device->fs_info->fs_devices->devices_kobj;
1869 devinfo_kobj = device->fs_info->fs_devices->devinfo_kobj;
1870 ASSERT(devices_kobj);
1871 ASSERT(devinfo_kobj);
1872
1873 nofs_flag = memalloc_nofs_save();
1874
1875 if (device->bdev) {
1876 struct kobject *disk_kobj = bdev_kobj(device->bdev);
1877
1878 ret = sysfs_create_link(devices_kobj, disk_kobj, disk_kobj->name);
1879 if (ret) {
1880 btrfs_warn(device->fs_info,
1881 "creating sysfs device link for devid %llu failed: %d",
1882 device->devid, ret);
1883 goto out;
1884 }
1885 }
1886
1887 init_completion(&device->kobj_unregister);
1888 ret = kobject_init_and_add(&device->devid_kobj, &devid_ktype,
1889 devinfo_kobj, "%llu", device->devid);
1890 if (ret) {
1891 kobject_put(&device->devid_kobj);
1892 btrfs_warn(device->fs_info,
1893 "devinfo init for devid %llu failed: %d",
1894 device->devid, ret);
1895 }
1896
1897 out:
1898 memalloc_nofs_restore(nofs_flag);
1899 return ret;
1900 }
1901
1902 static int btrfs_sysfs_add_fs_devices(struct btrfs_fs_devices *fs_devices)
1903 {
1904 int ret;
1905 struct btrfs_device *device;
1906 struct btrfs_fs_devices *seed;
1907
1908 list_for_each_entry(device, &fs_devices->devices, dev_list) {
1909 ret = btrfs_sysfs_add_device(device);
1910 if (ret)
1911 goto fail;
1912 }
1913
1914 list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
1915 list_for_each_entry(device, &seed->devices, dev_list) {
1916 ret = btrfs_sysfs_add_device(device);
1917 if (ret)
1918 goto fail;
1919 }
1920 }
1921
1922 return 0;
1923
1924 fail:
1925 btrfs_sysfs_remove_fs_devices(fs_devices);
1926 return ret;
1927 }
1928
1929 void btrfs_kobject_uevent(struct block_device *bdev, enum kobject_action action)
1930 {
1931 int ret;
1932
1933 ret = kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, action);
1934 if (ret)
1935 pr_warn("BTRFS: Sending event '%d' to kobject: '%s' (%p): failed\n",
1936 action, kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
1937 &disk_to_dev(bdev->bd_disk)->kobj);
1938 }
1939
1940 void btrfs_sysfs_update_sprout_fsid(struct btrfs_fs_devices *fs_devices)
1941
1942 {
1943 char fsid_buf[BTRFS_UUID_UNPARSED_SIZE];
1944
1945 /*
1946 * Sprouting changes fsid of the mounted filesystem, rename the fsid
1947 * directory
1948 */
1949 snprintf(fsid_buf, BTRFS_UUID_UNPARSED_SIZE, "%pU", fs_devices->fsid);
1950 if (kobject_rename(&fs_devices->fsid_kobj, fsid_buf))
1951 btrfs_warn(fs_devices->fs_info,
1952 "sysfs: failed to create fsid for sprout");
1953 }
1954
1955 void btrfs_sysfs_update_devid(struct btrfs_device *device)
1956 {
1957 char tmp[24];
1958
1959 snprintf(tmp, sizeof(tmp), "%llu", device->devid);
1960
1961 if (kobject_rename(&device->devid_kobj, tmp))
1962 btrfs_warn(device->fs_devices->fs_info,
1963 "sysfs: failed to update devid for %llu",
1964 device->devid);
1965 }
1966
1967 /* /sys/fs/btrfs/ entry */
1968 static struct kset *btrfs_kset;
1969
1970 /*
1971 * Creates:
1972 * /sys/fs/btrfs/UUID
1973 *
1974 * Can be called by the device discovery thread.
1975 */
1976 int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs)
1977 {
1978 int error;
1979
1980 init_completion(&fs_devs->kobj_unregister);
1981 fs_devs->fsid_kobj.kset = btrfs_kset;
1982 error = kobject_init_and_add(&fs_devs->fsid_kobj, &btrfs_ktype, NULL,
1983 "%pU", fs_devs->fsid);
1984 if (error) {
1985 kobject_put(&fs_devs->fsid_kobj);
1986 return error;
1987 }
1988
1989 fs_devs->devices_kobj = kobject_create_and_add("devices",
1990 &fs_devs->fsid_kobj);
1991 if (!fs_devs->devices_kobj) {
1992 btrfs_err(fs_devs->fs_info,
1993 "failed to init sysfs device interface");
1994 btrfs_sysfs_remove_fsid(fs_devs);
1995 return -ENOMEM;
1996 }
1997
1998 fs_devs->devinfo_kobj = kobject_create_and_add("devinfo",
1999 &fs_devs->fsid_kobj);
2000 if (!fs_devs->devinfo_kobj) {
2001 btrfs_err(fs_devs->fs_info,
2002 "failed to init sysfs devinfo kobject");
2003 btrfs_sysfs_remove_fsid(fs_devs);
2004 return -ENOMEM;
2005 }
2006
2007 return 0;
2008 }
2009
2010 int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info)
2011 {
2012 int error;
2013 struct btrfs_fs_devices *fs_devs = fs_info->fs_devices;
2014 struct kobject *fsid_kobj = &fs_devs->fsid_kobj;
2015
2016 error = btrfs_sysfs_add_fs_devices(fs_devs);
2017 if (error)
2018 return error;
2019
2020 error = sysfs_create_files(fsid_kobj, btrfs_attrs);
2021 if (error) {
2022 btrfs_sysfs_remove_fs_devices(fs_devs);
2023 return error;
2024 }
2025
2026 error = sysfs_create_group(fsid_kobj,
2027 &btrfs_feature_attr_group);
2028 if (error)
2029 goto failure;
2030
2031 #ifdef CONFIG_BTRFS_DEBUG
2032 fs_info->debug_kobj = kobject_create_and_add("debug", fsid_kobj);
2033 if (!fs_info->debug_kobj) {
2034 error = -ENOMEM;
2035 goto failure;
2036 }
2037
2038 error = sysfs_create_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
2039 if (error)
2040 goto failure;
2041 #endif
2042
2043 /* Discard directory */
2044 fs_info->discard_kobj = kobject_create_and_add("discard", fsid_kobj);
2045 if (!fs_info->discard_kobj) {
2046 error = -ENOMEM;
2047 goto failure;
2048 }
2049
2050 error = sysfs_create_files(fs_info->discard_kobj, discard_attrs);
2051 if (error)
2052 goto failure;
2053
2054 error = addrm_unknown_feature_attrs(fs_info, true);
2055 if (error)
2056 goto failure;
2057
2058 error = sysfs_create_link(fsid_kobj, &fs_info->sb->s_bdi->dev->kobj, "bdi");
2059 if (error)
2060 goto failure;
2061
2062 fs_info->space_info_kobj = kobject_create_and_add("allocation",
2063 fsid_kobj);
2064 if (!fs_info->space_info_kobj) {
2065 error = -ENOMEM;
2066 goto failure;
2067 }
2068
2069 error = sysfs_create_files(fs_info->space_info_kobj, allocation_attrs);
2070 if (error)
2071 goto failure;
2072
2073 return 0;
2074 failure:
2075 btrfs_sysfs_remove_mounted(fs_info);
2076 return error;
2077 }
2078
2079 static ssize_t qgroup_enabled_show(struct kobject *qgroups_kobj,
2080 struct kobj_attribute *a,
2081 char *buf)
2082 {
2083 struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
2084 bool enabled;
2085
2086 spin_lock(&fs_info->qgroup_lock);
2087 enabled = fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON;
2088 spin_unlock(&fs_info->qgroup_lock);
2089
2090 return sysfs_emit(buf, "%d\n", enabled);
2091 }
2092 BTRFS_ATTR(qgroups, enabled, qgroup_enabled_show);
2093
2094 static ssize_t qgroup_mode_show(struct kobject *qgroups_kobj,
2095 struct kobj_attribute *a,
2096 char *buf)
2097 {
2098 struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
2099 ssize_t ret = 0;
2100
2101 spin_lock(&fs_info->qgroup_lock);
2102 ASSERT(btrfs_qgroup_enabled(fs_info));
2103 switch (btrfs_qgroup_mode(fs_info)) {
2104 case BTRFS_QGROUP_MODE_FULL:
2105 ret = sysfs_emit(buf, "qgroup\n");
2106 break;
2107 case BTRFS_QGROUP_MODE_SIMPLE:
2108 ret = sysfs_emit(buf, "squota\n");
2109 break;
2110 default:
2111 btrfs_warn(fs_info, "unexpected qgroup mode %d\n",
2112 btrfs_qgroup_mode(fs_info));
2113 break;
2114 }
2115 spin_unlock(&fs_info->qgroup_lock);
2116
2117 return ret;
2118 }
2119 BTRFS_ATTR(qgroups, mode, qgroup_mode_show);
2120
2121 static ssize_t qgroup_inconsistent_show(struct kobject *qgroups_kobj,
2122 struct kobj_attribute *a,
2123 char *buf)
2124 {
2125 struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
2126 bool inconsistent;
2127
2128 spin_lock(&fs_info->qgroup_lock);
2129 inconsistent = (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT);
2130 spin_unlock(&fs_info->qgroup_lock);
2131
2132 return sysfs_emit(buf, "%d\n", inconsistent);
2133 }
2134 BTRFS_ATTR(qgroups, inconsistent, qgroup_inconsistent_show);
2135
2136 static ssize_t qgroup_drop_subtree_thres_show(struct kobject *qgroups_kobj,
2137 struct kobj_attribute *a,
2138 char *buf)
2139 {
2140 struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
2141 u8 result;
2142
2143 spin_lock(&fs_info->qgroup_lock);
2144 result = fs_info->qgroup_drop_subtree_thres;
2145 spin_unlock(&fs_info->qgroup_lock);
2146
2147 return sysfs_emit(buf, "%d\n", result);
2148 }
2149
2150 static ssize_t qgroup_drop_subtree_thres_store(struct kobject *qgroups_kobj,
2151 struct kobj_attribute *a,
2152 const char *buf, size_t len)
2153 {
2154 struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
2155 u8 new_thres;
2156 int ret;
2157
2158 ret = kstrtou8(buf, 10, &new_thres);
2159 if (ret)
2160 return -EINVAL;
2161
2162 if (new_thres > BTRFS_MAX_LEVEL)
2163 return -EINVAL;
2164
2165 spin_lock(&fs_info->qgroup_lock);
2166 fs_info->qgroup_drop_subtree_thres = new_thres;
2167 spin_unlock(&fs_info->qgroup_lock);
2168
2169 return len;
2170 }
2171 BTRFS_ATTR_RW(qgroups, drop_subtree_threshold, qgroup_drop_subtree_thres_show,
2172 qgroup_drop_subtree_thres_store);
2173
2174 /*
2175 * Qgroups global info
2176 *
2177 * Path: /sys/fs/btrfs/<uuid>/qgroups/
2178 */
2179 static struct attribute *qgroups_attrs[] = {
2180 BTRFS_ATTR_PTR(qgroups, enabled),
2181 BTRFS_ATTR_PTR(qgroups, inconsistent),
2182 BTRFS_ATTR_PTR(qgroups, drop_subtree_threshold),
2183 BTRFS_ATTR_PTR(qgroups, mode),
2184 NULL
2185 };
2186 ATTRIBUTE_GROUPS(qgroups);
2187
2188 static void qgroups_release(struct kobject *kobj)
2189 {
2190 kfree(kobj);
2191 }
2192
2193 static const struct kobj_type qgroups_ktype = {
2194 .sysfs_ops = &kobj_sysfs_ops,
2195 .default_groups = qgroups_groups,
2196 .release = qgroups_release,
2197 };
2198
2199 static inline struct btrfs_fs_info *qgroup_kobj_to_fs_info(struct kobject *kobj)
2200 {
2201 return to_fs_info(kobj->parent->parent);
2202 }
2203
2204 #define QGROUP_ATTR(_member, _show_name) \
2205 static ssize_t btrfs_qgroup_show_##_member(struct kobject *qgroup_kobj, \
2206 struct kobj_attribute *a, \
2207 char *buf) \
2208 { \
2209 struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj); \
2210 struct btrfs_qgroup *qgroup = container_of(qgroup_kobj, \
2211 struct btrfs_qgroup, kobj); \
2212 return btrfs_show_u64(&qgroup->_member, &fs_info->qgroup_lock, buf); \
2213 } \
2214 BTRFS_ATTR(qgroup, _show_name, btrfs_qgroup_show_##_member)
2215
2216 #define QGROUP_RSV_ATTR(_name, _type) \
2217 static ssize_t btrfs_qgroup_rsv_show_##_name(struct kobject *qgroup_kobj, \
2218 struct kobj_attribute *a, \
2219 char *buf) \
2220 { \
2221 struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj); \
2222 struct btrfs_qgroup *qgroup = container_of(qgroup_kobj, \
2223 struct btrfs_qgroup, kobj); \
2224 return btrfs_show_u64(&qgroup->rsv.values[_type], \
2225 &fs_info->qgroup_lock, buf); \
2226 } \
2227 BTRFS_ATTR(qgroup, rsv_##_name, btrfs_qgroup_rsv_show_##_name)
2228
2229 QGROUP_ATTR(rfer, referenced);
2230 QGROUP_ATTR(excl, exclusive);
2231 QGROUP_ATTR(max_rfer, max_referenced);
2232 QGROUP_ATTR(max_excl, max_exclusive);
2233 QGROUP_ATTR(lim_flags, limit_flags);
2234 QGROUP_RSV_ATTR(data, BTRFS_QGROUP_RSV_DATA);
2235 QGROUP_RSV_ATTR(meta_pertrans, BTRFS_QGROUP_RSV_META_PERTRANS);
2236 QGROUP_RSV_ATTR(meta_prealloc, BTRFS_QGROUP_RSV_META_PREALLOC);
2237
2238 /*
2239 * Qgroup information.
2240 *
2241 * Path: /sys/fs/btrfs/<uuid>/qgroups/<level>_<qgroupid>/
2242 */
2243 static struct attribute *qgroup_attrs[] = {
2244 BTRFS_ATTR_PTR(qgroup, referenced),
2245 BTRFS_ATTR_PTR(qgroup, exclusive),
2246 BTRFS_ATTR_PTR(qgroup, max_referenced),
2247 BTRFS_ATTR_PTR(qgroup, max_exclusive),
2248 BTRFS_ATTR_PTR(qgroup, limit_flags),
2249 BTRFS_ATTR_PTR(qgroup, rsv_data),
2250 BTRFS_ATTR_PTR(qgroup, rsv_meta_pertrans),
2251 BTRFS_ATTR_PTR(qgroup, rsv_meta_prealloc),
2252 NULL
2253 };
2254 ATTRIBUTE_GROUPS(qgroup);
2255
2256 static void qgroup_release(struct kobject *kobj)
2257 {
2258 struct btrfs_qgroup *qgroup = container_of(kobj, struct btrfs_qgroup, kobj);
2259
2260 memset(&qgroup->kobj, 0, sizeof(*kobj));
2261 }
2262
2263 static const struct kobj_type qgroup_ktype = {
2264 .sysfs_ops = &kobj_sysfs_ops,
2265 .release = qgroup_release,
2266 .default_groups = qgroup_groups,
2267 };
2268
2269 int btrfs_sysfs_add_one_qgroup(struct btrfs_fs_info *fs_info,
2270 struct btrfs_qgroup *qgroup)
2271 {
2272 struct kobject *qgroups_kobj = fs_info->qgroups_kobj;
2273 int ret;
2274
2275 if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
2276 return 0;
2277 if (qgroup->kobj.state_initialized)
2278 return 0;
2279 if (!qgroups_kobj)
2280 return -EINVAL;
2281
2282 ret = kobject_init_and_add(&qgroup->kobj, &qgroup_ktype, qgroups_kobj,
2283 "%hu_%llu", btrfs_qgroup_level(qgroup->qgroupid),
2284 btrfs_qgroup_subvolid(qgroup->qgroupid));
2285 if (ret < 0)
2286 kobject_put(&qgroup->kobj);
2287
2288 return ret;
2289 }
2290
2291 void btrfs_sysfs_del_qgroups(struct btrfs_fs_info *fs_info)
2292 {
2293 struct btrfs_qgroup *qgroup;
2294 struct btrfs_qgroup *next;
2295
2296 if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
2297 return;
2298
2299 rbtree_postorder_for_each_entry_safe(qgroup, next,
2300 &fs_info->qgroup_tree, node)
2301 btrfs_sysfs_del_one_qgroup(fs_info, qgroup);
2302 if (fs_info->qgroups_kobj) {
2303 kobject_del(fs_info->qgroups_kobj);
2304 kobject_put(fs_info->qgroups_kobj);
2305 fs_info->qgroups_kobj = NULL;
2306 }
2307 }
2308
2309 /* Called when qgroups get initialized, thus there is no need for locking */
2310 int btrfs_sysfs_add_qgroups(struct btrfs_fs_info *fs_info)
2311 {
2312 struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
2313 struct btrfs_qgroup *qgroup;
2314 struct btrfs_qgroup *next;
2315 int ret = 0;
2316
2317 if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
2318 return 0;
2319
2320 ASSERT(fsid_kobj);
2321 if (fs_info->qgroups_kobj)
2322 return 0;
2323
2324 fs_info->qgroups_kobj = kzalloc(sizeof(struct kobject), GFP_KERNEL);
2325 if (!fs_info->qgroups_kobj)
2326 return -ENOMEM;
2327
2328 ret = kobject_init_and_add(fs_info->qgroups_kobj, &qgroups_ktype,
2329 fsid_kobj, "qgroups");
2330 if (ret < 0)
2331 goto out;
2332
2333 rbtree_postorder_for_each_entry_safe(qgroup, next,
2334 &fs_info->qgroup_tree, node) {
2335 ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
2336 if (ret < 0)
2337 goto out;
2338 }
2339
2340 out:
2341 if (ret < 0)
2342 btrfs_sysfs_del_qgroups(fs_info);
2343 return ret;
2344 }
2345
2346 void btrfs_sysfs_del_one_qgroup(struct btrfs_fs_info *fs_info,
2347 struct btrfs_qgroup *qgroup)
2348 {
2349 if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
2350 return;
2351
2352 if (qgroup->kobj.state_initialized) {
2353 kobject_del(&qgroup->kobj);
2354 kobject_put(&qgroup->kobj);
2355 }
2356 }
2357
2358 /*
2359 * Change per-fs features in /sys/fs/btrfs/UUID/features to match current
2360 * values in superblock. Call after any changes to incompat/compat_ro flags
2361 */
2362 void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info)
2363 {
2364 struct kobject *fsid_kobj;
2365 int ret;
2366
2367 if (!fs_info)
2368 return;
2369
2370 fsid_kobj = &fs_info->fs_devices->fsid_kobj;
2371 if (!fsid_kobj->state_initialized)
2372 return;
2373
2374 ret = sysfs_update_group(fsid_kobj, &btrfs_feature_attr_group);
2375 if (ret < 0)
2376 btrfs_warn(fs_info,
2377 "failed to update /sys/fs/btrfs/%pU/features: %d",
2378 fs_info->fs_devices->fsid, ret);
2379 }
2380
2381 int __init btrfs_init_sysfs(void)
2382 {
2383 int ret;
2384
2385 btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj);
2386 if (!btrfs_kset)
2387 return -ENOMEM;
2388
2389 init_feature_attrs();
2390 ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2391 if (ret)
2392 goto out2;
2393 ret = sysfs_merge_group(&btrfs_kset->kobj,
2394 &btrfs_static_feature_attr_group);
2395 if (ret)
2396 goto out_remove_group;
2397
2398 #ifdef CONFIG_BTRFS_DEBUG
2399 ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
2400 if (ret) {
2401 sysfs_unmerge_group(&btrfs_kset->kobj,
2402 &btrfs_static_feature_attr_group);
2403 goto out_remove_group;
2404 }
2405 #endif
2406
2407 return 0;
2408
2409 out_remove_group:
2410 sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2411 out2:
2412 kset_unregister(btrfs_kset);
2413
2414 return ret;
2415 }
2416
2417 void __cold btrfs_exit_sysfs(void)
2418 {
2419 sysfs_unmerge_group(&btrfs_kset->kobj,
2420 &btrfs_static_feature_attr_group);
2421 sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2422 #ifdef CONFIG_BTRFS_DEBUG
2423 sysfs_remove_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
2424 #endif
2425 kset_unregister(btrfs_kset);
2426 }
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