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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/slab.h>
8#include <linux/spinlock.h>
9#include <linux/completion.h>
10#include <linux/buffer_head.h>
11#include <linux/kobject.h>
12#include <linux/bug.h>
13#include <linux/genhd.h>
14#include <linux/debugfs.h>
15
16#include "ctree.h"
17#include "disk-io.h"
18#include "transaction.h"
19#include "sysfs.h"
20#include "volumes.h"
21
22static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj);
23static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj);
24
25static u64 get_features(struct btrfs_fs_info *fs_info,
26 enum btrfs_feature_set set)
27{
28 struct btrfs_super_block *disk_super = fs_info->super_copy;
29 if (set == FEAT_COMPAT)
30 return btrfs_super_compat_flags(disk_super);
31 else if (set == FEAT_COMPAT_RO)
32 return btrfs_super_compat_ro_flags(disk_super);
33 else
34 return btrfs_super_incompat_flags(disk_super);
35}
36
37static void set_features(struct btrfs_fs_info *fs_info,
38 enum btrfs_feature_set set, u64 features)
39{
40 struct btrfs_super_block *disk_super = fs_info->super_copy;
41 if (set == FEAT_COMPAT)
42 btrfs_set_super_compat_flags(disk_super, features);
43 else if (set == FEAT_COMPAT_RO)
44 btrfs_set_super_compat_ro_flags(disk_super, features);
45 else
46 btrfs_set_super_incompat_flags(disk_super, features);
47}
48
49static int can_modify_feature(struct btrfs_feature_attr *fa)
50{
51 int val = 0;
52 u64 set, clear;
53 switch (fa->feature_set) {
54 case FEAT_COMPAT:
55 set = BTRFS_FEATURE_COMPAT_SAFE_SET;
56 clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
57 break;
58 case FEAT_COMPAT_RO:
59 set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
60 clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
61 break;
62 case FEAT_INCOMPAT:
63 set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
64 clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
65 break;
66 default:
67 pr_warn("btrfs: sysfs: unknown feature set %d\n",
68 fa->feature_set);
69 return 0;
70 }
71
72 if (set & fa->feature_bit)
73 val |= 1;
74 if (clear & fa->feature_bit)
75 val |= 2;
76
77 return val;
78}
79
80static ssize_t btrfs_feature_attr_show(struct kobject *kobj,
81 struct kobj_attribute *a, char *buf)
82{
83 int val = 0;
84 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
85 struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
86 if (fs_info) {
87 u64 features = get_features(fs_info, fa->feature_set);
88 if (features & fa->feature_bit)
89 val = 1;
90 } else
91 val = can_modify_feature(fa);
92
93 return snprintf(buf, PAGE_SIZE, "%d\n", val);
94}
95
96static ssize_t btrfs_feature_attr_store(struct kobject *kobj,
97 struct kobj_attribute *a,
98 const char *buf, size_t count)
99{
100 struct btrfs_fs_info *fs_info;
101 struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
102 u64 features, set, clear;
103 unsigned long val;
104 int ret;
105
106 fs_info = to_fs_info(kobj);
107 if (!fs_info)
108 return -EPERM;
109
110 if (sb_rdonly(fs_info->sb))
111 return -EROFS;
112
113 ret = kstrtoul(skip_spaces(buf), 0, &val);
114 if (ret)
115 return ret;
116
117 if (fa->feature_set == FEAT_COMPAT) {
118 set = BTRFS_FEATURE_COMPAT_SAFE_SET;
119 clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
120 } else if (fa->feature_set == FEAT_COMPAT_RO) {
121 set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
122 clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
123 } else {
124 set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
125 clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
126 }
127
128 features = get_features(fs_info, fa->feature_set);
129
130 /* Nothing to do */
131 if ((val && (features & fa->feature_bit)) ||
132 (!val && !(features & fa->feature_bit)))
133 return count;
134
135 if ((val && !(set & fa->feature_bit)) ||
136 (!val && !(clear & fa->feature_bit))) {
137 btrfs_info(fs_info,
138 "%sabling feature %s on mounted fs is not supported.",
139 val ? "En" : "Dis", fa->kobj_attr.attr.name);
140 return -EPERM;
141 }
142
143 btrfs_info(fs_info, "%s %s feature flag",
144 val ? "Setting" : "Clearing", fa->kobj_attr.attr.name);
145
146 spin_lock(&fs_info->super_lock);
147 features = get_features(fs_info, fa->feature_set);
148 if (val)
149 features |= fa->feature_bit;
150 else
151 features &= ~fa->feature_bit;
152 set_features(fs_info, fa->feature_set, features);
153 spin_unlock(&fs_info->super_lock);
154
155 /*
156 * We don't want to do full transaction commit from inside sysfs
157 */
158 btrfs_set_pending(fs_info, COMMIT);
159 wake_up_process(fs_info->transaction_kthread);
160
161 return count;
162}
163
164static umode_t btrfs_feature_visible(struct kobject *kobj,
165 struct attribute *attr, int unused)
166{
167 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
168 umode_t mode = attr->mode;
169
170 if (fs_info) {
171 struct btrfs_feature_attr *fa;
172 u64 features;
173
174 fa = attr_to_btrfs_feature_attr(attr);
175 features = get_features(fs_info, fa->feature_set);
176
177 if (can_modify_feature(fa))
178 mode |= S_IWUSR;
179 else if (!(features & fa->feature_bit))
180 mode = 0;
181 }
182
183 return mode;
184}
185
186BTRFS_FEAT_ATTR_INCOMPAT(mixed_backref, MIXED_BACKREF);
187BTRFS_FEAT_ATTR_INCOMPAT(default_subvol, DEFAULT_SUBVOL);
188BTRFS_FEAT_ATTR_INCOMPAT(mixed_groups, MIXED_GROUPS);
189BTRFS_FEAT_ATTR_INCOMPAT(compress_lzo, COMPRESS_LZO);
190BTRFS_FEAT_ATTR_INCOMPAT(compress_zstd, COMPRESS_ZSTD);
191BTRFS_FEAT_ATTR_INCOMPAT(big_metadata, BIG_METADATA);
192BTRFS_FEAT_ATTR_INCOMPAT(extended_iref, EXTENDED_IREF);
193BTRFS_FEAT_ATTR_INCOMPAT(raid56, RAID56);
194BTRFS_FEAT_ATTR_INCOMPAT(skinny_metadata, SKINNY_METADATA);
195BTRFS_FEAT_ATTR_INCOMPAT(no_holes, NO_HOLES);
196BTRFS_FEAT_ATTR_COMPAT_RO(free_space_tree, FREE_SPACE_TREE);
197
198static struct attribute *btrfs_supported_feature_attrs[] = {
199 BTRFS_FEAT_ATTR_PTR(mixed_backref),
200 BTRFS_FEAT_ATTR_PTR(default_subvol),
201 BTRFS_FEAT_ATTR_PTR(mixed_groups),
202 BTRFS_FEAT_ATTR_PTR(compress_lzo),
203 BTRFS_FEAT_ATTR_PTR(compress_zstd),
204 BTRFS_FEAT_ATTR_PTR(big_metadata),
205 BTRFS_FEAT_ATTR_PTR(extended_iref),
206 BTRFS_FEAT_ATTR_PTR(raid56),
207 BTRFS_FEAT_ATTR_PTR(skinny_metadata),
208 BTRFS_FEAT_ATTR_PTR(no_holes),
209 BTRFS_FEAT_ATTR_PTR(free_space_tree),
210 NULL
211};
212
213static const struct attribute_group btrfs_feature_attr_group = {
214 .name = "features",
215 .is_visible = btrfs_feature_visible,
216 .attrs = btrfs_supported_feature_attrs,
217};
218
219static ssize_t btrfs_show_u64(u64 *value_ptr, spinlock_t *lock, char *buf)
220{
221 u64 val;
222 if (lock)
223 spin_lock(lock);
224 val = *value_ptr;
225 if (lock)
226 spin_unlock(lock);
227 return snprintf(buf, PAGE_SIZE, "%llu\n", val);
228}
229
230static ssize_t global_rsv_size_show(struct kobject *kobj,
231 struct kobj_attribute *ka, char *buf)
232{
233 struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
234 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
235 return btrfs_show_u64(&block_rsv->size, &block_rsv->lock, buf);
236}
237BTRFS_ATTR(allocation, global_rsv_size, global_rsv_size_show);
238
239static ssize_t global_rsv_reserved_show(struct kobject *kobj,
240 struct kobj_attribute *a, char *buf)
241{
242 struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
243 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
244 return btrfs_show_u64(&block_rsv->reserved, &block_rsv->lock, buf);
245}
246BTRFS_ATTR(allocation, global_rsv_reserved, global_rsv_reserved_show);
247
248#define to_space_info(_kobj) container_of(_kobj, struct btrfs_space_info, kobj)
249#define to_raid_kobj(_kobj) container_of(_kobj, struct raid_kobject, kobj)
250
251static ssize_t raid_bytes_show(struct kobject *kobj,
252 struct kobj_attribute *attr, char *buf);
253BTRFS_ATTR(raid, total_bytes, raid_bytes_show);
254BTRFS_ATTR(raid, used_bytes, raid_bytes_show);
255
256static ssize_t raid_bytes_show(struct kobject *kobj,
257 struct kobj_attribute *attr, char *buf)
258
259{
260 struct btrfs_space_info *sinfo = to_space_info(kobj->parent);
261 struct btrfs_block_group_cache *block_group;
262 int index = btrfs_bg_flags_to_raid_index(to_raid_kobj(kobj)->flags);
263 u64 val = 0;
264
265 down_read(&sinfo->groups_sem);
266 list_for_each_entry(block_group, &sinfo->block_groups[index], list) {
267 if (&attr->attr == BTRFS_ATTR_PTR(raid, total_bytes))
268 val += block_group->key.offset;
269 else
270 val += btrfs_block_group_used(&block_group->item);
271 }
272 up_read(&sinfo->groups_sem);
273 return snprintf(buf, PAGE_SIZE, "%llu\n", val);
274}
275
276static struct attribute *raid_attributes[] = {
277 BTRFS_ATTR_PTR(raid, total_bytes),
278 BTRFS_ATTR_PTR(raid, used_bytes),
279 NULL
280};
281
282static void release_raid_kobj(struct kobject *kobj)
283{
284 kfree(to_raid_kobj(kobj));
285}
286
287struct kobj_type btrfs_raid_ktype = {
288 .sysfs_ops = &kobj_sysfs_ops,
289 .release = release_raid_kobj,
290 .default_attrs = raid_attributes,
291};
292
293#define SPACE_INFO_ATTR(field) \
294static ssize_t btrfs_space_info_show_##field(struct kobject *kobj, \
295 struct kobj_attribute *a, \
296 char *buf) \
297{ \
298 struct btrfs_space_info *sinfo = to_space_info(kobj); \
299 return btrfs_show_u64(&sinfo->field, &sinfo->lock, buf); \
300} \
301BTRFS_ATTR(space_info, field, btrfs_space_info_show_##field)
302
303static ssize_t btrfs_space_info_show_total_bytes_pinned(struct kobject *kobj,
304 struct kobj_attribute *a,
305 char *buf)
306{
307 struct btrfs_space_info *sinfo = to_space_info(kobj);
308 s64 val = percpu_counter_sum(&sinfo->total_bytes_pinned);
309 return snprintf(buf, PAGE_SIZE, "%lld\n", val);
310}
311
312SPACE_INFO_ATTR(flags);
313SPACE_INFO_ATTR(total_bytes);
314SPACE_INFO_ATTR(bytes_used);
315SPACE_INFO_ATTR(bytes_pinned);
316SPACE_INFO_ATTR(bytes_reserved);
317SPACE_INFO_ATTR(bytes_may_use);
318SPACE_INFO_ATTR(bytes_readonly);
319SPACE_INFO_ATTR(disk_used);
320SPACE_INFO_ATTR(disk_total);
321BTRFS_ATTR(space_info, total_bytes_pinned,
322 btrfs_space_info_show_total_bytes_pinned);
323
324static struct attribute *space_info_attrs[] = {
325 BTRFS_ATTR_PTR(space_info, flags),
326 BTRFS_ATTR_PTR(space_info, total_bytes),
327 BTRFS_ATTR_PTR(space_info, bytes_used),
328 BTRFS_ATTR_PTR(space_info, bytes_pinned),
329 BTRFS_ATTR_PTR(space_info, bytes_reserved),
330 BTRFS_ATTR_PTR(space_info, bytes_may_use),
331 BTRFS_ATTR_PTR(space_info, bytes_readonly),
332 BTRFS_ATTR_PTR(space_info, disk_used),
333 BTRFS_ATTR_PTR(space_info, disk_total),
334 BTRFS_ATTR_PTR(space_info, total_bytes_pinned),
335 NULL,
336};
337
338static void space_info_release(struct kobject *kobj)
339{
340 struct btrfs_space_info *sinfo = to_space_info(kobj);
341 percpu_counter_destroy(&sinfo->total_bytes_pinned);
342 kfree(sinfo);
343}
344
345struct kobj_type space_info_ktype = {
346 .sysfs_ops = &kobj_sysfs_ops,
347 .release = space_info_release,
348 .default_attrs = space_info_attrs,
349};
350
351static const struct attribute *allocation_attrs[] = {
352 BTRFS_ATTR_PTR(allocation, global_rsv_reserved),
353 BTRFS_ATTR_PTR(allocation, global_rsv_size),
354 NULL,
355};
356
357static ssize_t btrfs_label_show(struct kobject *kobj,
358 struct kobj_attribute *a, char *buf)
359{
360 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
361 char *label = fs_info->super_copy->label;
362 ssize_t ret;
363
364 spin_lock(&fs_info->super_lock);
365 ret = snprintf(buf, PAGE_SIZE, label[0] ? "%s\n" : "%s", label);
366 spin_unlock(&fs_info->super_lock);
367
368 return ret;
369}
370
371static ssize_t btrfs_label_store(struct kobject *kobj,
372 struct kobj_attribute *a,
373 const char *buf, size_t len)
374{
375 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
376 size_t p_len;
377
378 if (!fs_info)
379 return -EPERM;
380
381 if (sb_rdonly(fs_info->sb))
382 return -EROFS;
383
384 /*
385 * p_len is the len until the first occurrence of either
386 * '\n' or '\0'
387 */
388 p_len = strcspn(buf, "\n");
389
390 if (p_len >= BTRFS_LABEL_SIZE)
391 return -EINVAL;
392
393 spin_lock(&fs_info->super_lock);
394 memset(fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE);
395 memcpy(fs_info->super_copy->label, buf, p_len);
396 spin_unlock(&fs_info->super_lock);
397
398 /*
399 * We don't want to do full transaction commit from inside sysfs
400 */
401 btrfs_set_pending(fs_info, COMMIT);
402 wake_up_process(fs_info->transaction_kthread);
403
404 return len;
405}
406BTRFS_ATTR_RW(, label, btrfs_label_show, btrfs_label_store);
407
408static ssize_t btrfs_nodesize_show(struct kobject *kobj,
409 struct kobj_attribute *a, char *buf)
410{
411 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
412
413 return snprintf(buf, PAGE_SIZE, "%u\n", fs_info->super_copy->nodesize);
414}
415
416BTRFS_ATTR(, nodesize, btrfs_nodesize_show);
417
418static ssize_t btrfs_sectorsize_show(struct kobject *kobj,
419 struct kobj_attribute *a, char *buf)
420{
421 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
422
423 return snprintf(buf, PAGE_SIZE, "%u\n",
424 fs_info->super_copy->sectorsize);
425}
426
427BTRFS_ATTR(, sectorsize, btrfs_sectorsize_show);
428
429static ssize_t btrfs_clone_alignment_show(struct kobject *kobj,
430 struct kobj_attribute *a, char *buf)
431{
432 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
433
434 return snprintf(buf, PAGE_SIZE, "%u\n",
435 fs_info->super_copy->sectorsize);
436}
437
438BTRFS_ATTR(, clone_alignment, btrfs_clone_alignment_show);
439
440static ssize_t quota_override_show(struct kobject *kobj,
441 struct kobj_attribute *a, char *buf)
442{
443 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
444 int quota_override;
445
446 quota_override = test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
447 return snprintf(buf, PAGE_SIZE, "%d\n", quota_override);
448}
449
450static ssize_t quota_override_store(struct kobject *kobj,
451 struct kobj_attribute *a,
452 const char *buf, size_t len)
453{
454 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
455 unsigned long knob;
456 int err;
457
458 if (!fs_info)
459 return -EPERM;
460
461 if (!capable(CAP_SYS_RESOURCE))
462 return -EPERM;
463
464 err = kstrtoul(buf, 10, &knob);
465 if (err)
466 return err;
467 if (knob > 1)
468 return -EINVAL;
469
470 if (knob)
471 set_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
472 else
473 clear_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
474
475 return len;
476}
477
478BTRFS_ATTR_RW(, quota_override, quota_override_show, quota_override_store);
479
480static const struct attribute *btrfs_attrs[] = {
481 BTRFS_ATTR_PTR(, label),
482 BTRFS_ATTR_PTR(, nodesize),
483 BTRFS_ATTR_PTR(, sectorsize),
484 BTRFS_ATTR_PTR(, clone_alignment),
485 BTRFS_ATTR_PTR(, quota_override),
486 NULL,
487};
488
489static void btrfs_release_fsid_kobj(struct kobject *kobj)
490{
491 struct btrfs_fs_devices *fs_devs = to_fs_devs(kobj);
492
493 memset(&fs_devs->fsid_kobj, 0, sizeof(struct kobject));
494 complete(&fs_devs->kobj_unregister);
495}
496
497static struct kobj_type btrfs_ktype = {
498 .sysfs_ops = &kobj_sysfs_ops,
499 .release = btrfs_release_fsid_kobj,
500};
501
502static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj)
503{
504 if (kobj->ktype != &btrfs_ktype)
505 return NULL;
506 return container_of(kobj, struct btrfs_fs_devices, fsid_kobj);
507}
508
509static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)
510{
511 if (kobj->ktype != &btrfs_ktype)
512 return NULL;
513 return to_fs_devs(kobj)->fs_info;
514}
515
516#define NUM_FEATURE_BITS 64
517static char btrfs_unknown_feature_names[3][NUM_FEATURE_BITS][13];
518static struct btrfs_feature_attr btrfs_feature_attrs[3][NUM_FEATURE_BITS];
519
520static const u64 supported_feature_masks[3] = {
521 [FEAT_COMPAT] = BTRFS_FEATURE_COMPAT_SUPP,
522 [FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP,
523 [FEAT_INCOMPAT] = BTRFS_FEATURE_INCOMPAT_SUPP,
524};
525
526static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add)
527{
528 int set;
529
530 for (set = 0; set < FEAT_MAX; set++) {
531 int i;
532 struct attribute *attrs[2];
533 struct attribute_group agroup = {
534 .name = "features",
535 .attrs = attrs,
536 };
537 u64 features = get_features(fs_info, set);
538 features &= ~supported_feature_masks[set];
539
540 if (!features)
541 continue;
542
543 attrs[1] = NULL;
544 for (i = 0; i < NUM_FEATURE_BITS; i++) {
545 struct btrfs_feature_attr *fa;
546
547 if (!(features & (1ULL << i)))
548 continue;
549
550 fa = &btrfs_feature_attrs[set][i];
551 attrs[0] = &fa->kobj_attr.attr;
552 if (add) {
553 int ret;
554 ret = sysfs_merge_group(&fs_info->fs_devices->fsid_kobj,
555 &agroup);
556 if (ret)
557 return ret;
558 } else
559 sysfs_unmerge_group(&fs_info->fs_devices->fsid_kobj,
560 &agroup);
561 }
562
563 }
564 return 0;
565}
566
567static void __btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
568{
569 if (fs_devs->device_dir_kobj) {
570 kobject_del(fs_devs->device_dir_kobj);
571 kobject_put(fs_devs->device_dir_kobj);
572 fs_devs->device_dir_kobj = NULL;
573 }
574
575 if (fs_devs->fsid_kobj.state_initialized) {
576 kobject_del(&fs_devs->fsid_kobj);
577 kobject_put(&fs_devs->fsid_kobj);
578 wait_for_completion(&fs_devs->kobj_unregister);
579 }
580}
581
582/* when fs_devs is NULL it will remove all fsid kobject */
583void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
584{
585 struct list_head *fs_uuids = btrfs_get_fs_uuids();
586
587 if (fs_devs) {
588 __btrfs_sysfs_remove_fsid(fs_devs);
589 return;
590 }
591
592 list_for_each_entry(fs_devs, fs_uuids, list) {
593 __btrfs_sysfs_remove_fsid(fs_devs);
594 }
595}
596
597void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info)
598{
599 btrfs_reset_fs_info_ptr(fs_info);
600
601 if (fs_info->space_info_kobj) {
602 sysfs_remove_files(fs_info->space_info_kobj, allocation_attrs);
603 kobject_del(fs_info->space_info_kobj);
604 kobject_put(fs_info->space_info_kobj);
605 }
606 addrm_unknown_feature_attrs(fs_info, false);
607 sysfs_remove_group(&fs_info->fs_devices->fsid_kobj, &btrfs_feature_attr_group);
608 sysfs_remove_files(&fs_info->fs_devices->fsid_kobj, btrfs_attrs);
609 btrfs_sysfs_rm_device_link(fs_info->fs_devices, NULL);
610}
611
612const char * const btrfs_feature_set_names[3] = {
613 [FEAT_COMPAT] = "compat",
614 [FEAT_COMPAT_RO] = "compat_ro",
615 [FEAT_INCOMPAT] = "incompat",
616};
617
618char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags)
619{
620 size_t bufsize = 4096; /* safe max, 64 names * 64 bytes */
621 int len = 0;
622 int i;
623 char *str;
624
625 str = kmalloc(bufsize, GFP_KERNEL);
626 if (!str)
627 return str;
628
629 for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
630 const char *name;
631
632 if (!(flags & (1ULL << i)))
633 continue;
634
635 name = btrfs_feature_attrs[set][i].kobj_attr.attr.name;
636 len += snprintf(str + len, bufsize - len, "%s%s",
637 len ? "," : "", name);
638 }
639
640 return str;
641}
642
643static void init_feature_attrs(void)
644{
645 struct btrfs_feature_attr *fa;
646 int set, i;
647
648 BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names) !=
649 ARRAY_SIZE(btrfs_feature_attrs));
650 BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names[0]) !=
651 ARRAY_SIZE(btrfs_feature_attrs[0]));
652
653 memset(btrfs_feature_attrs, 0, sizeof(btrfs_feature_attrs));
654 memset(btrfs_unknown_feature_names, 0,
655 sizeof(btrfs_unknown_feature_names));
656
657 for (i = 0; btrfs_supported_feature_attrs[i]; i++) {
658 struct btrfs_feature_attr *sfa;
659 struct attribute *a = btrfs_supported_feature_attrs[i];
660 int bit;
661 sfa = attr_to_btrfs_feature_attr(a);
662 bit = ilog2(sfa->feature_bit);
663 fa = &btrfs_feature_attrs[sfa->feature_set][bit];
664
665 fa->kobj_attr.attr.name = sfa->kobj_attr.attr.name;
666 }
667
668 for (set = 0; set < FEAT_MAX; set++) {
669 for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
670 char *name = btrfs_unknown_feature_names[set][i];
671 fa = &btrfs_feature_attrs[set][i];
672
673 if (fa->kobj_attr.attr.name)
674 continue;
675
676 snprintf(name, 13, "%s:%u",
677 btrfs_feature_set_names[set], i);
678
679 fa->kobj_attr.attr.name = name;
680 fa->kobj_attr.attr.mode = S_IRUGO;
681 fa->feature_set = set;
682 fa->feature_bit = 1ULL << i;
683 }
684 }
685}
686
687/* when one_device is NULL, it removes all device links */
688
689int btrfs_sysfs_rm_device_link(struct btrfs_fs_devices *fs_devices,
690 struct btrfs_device *one_device)
691{
692 struct hd_struct *disk;
693 struct kobject *disk_kobj;
694
695 if (!fs_devices->device_dir_kobj)
696 return -EINVAL;
697
698 if (one_device && one_device->bdev) {
699 disk = one_device->bdev->bd_part;
700 disk_kobj = &part_to_dev(disk)->kobj;
701
702 sysfs_remove_link(fs_devices->device_dir_kobj,
703 disk_kobj->name);
704 }
705
706 if (one_device)
707 return 0;
708
709 list_for_each_entry(one_device,
710 &fs_devices->devices, dev_list) {
711 if (!one_device->bdev)
712 continue;
713 disk = one_device->bdev->bd_part;
714 disk_kobj = &part_to_dev(disk)->kobj;
715
716 sysfs_remove_link(fs_devices->device_dir_kobj,
717 disk_kobj->name);
718 }
719
720 return 0;
721}
722
723int btrfs_sysfs_add_device(struct btrfs_fs_devices *fs_devs)
724{
725 if (!fs_devs->device_dir_kobj)
726 fs_devs->device_dir_kobj = kobject_create_and_add("devices",
727 &fs_devs->fsid_kobj);
728
729 if (!fs_devs->device_dir_kobj)
730 return -ENOMEM;
731
732 return 0;
733}
734
735int btrfs_sysfs_add_device_link(struct btrfs_fs_devices *fs_devices,
736 struct btrfs_device *one_device)
737{
738 int error = 0;
739 struct btrfs_device *dev;
740
741 list_for_each_entry(dev, &fs_devices->devices, dev_list) {
742 struct hd_struct *disk;
743 struct kobject *disk_kobj;
744
745 if (!dev->bdev)
746 continue;
747
748 if (one_device && one_device != dev)
749 continue;
750
751 disk = dev->bdev->bd_part;
752 disk_kobj = &part_to_dev(disk)->kobj;
753
754 error = sysfs_create_link(fs_devices->device_dir_kobj,
755 disk_kobj, disk_kobj->name);
756 if (error)
757 break;
758 }
759
760 return error;
761}
762
763/* /sys/fs/btrfs/ entry */
764static struct kset *btrfs_kset;
765
766/* /sys/kernel/debug/btrfs */
767static struct dentry *btrfs_debugfs_root_dentry;
768
769/* Debugging tunables and exported data */
770u64 btrfs_debugfs_test;
771
772/*
773 * Can be called by the device discovery thread.
774 * And parent can be specified for seed device
775 */
776int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs,
777 struct kobject *parent)
778{
779 int error;
780
781 init_completion(&fs_devs->kobj_unregister);
782 fs_devs->fsid_kobj.kset = btrfs_kset;
783 error = kobject_init_and_add(&fs_devs->fsid_kobj,
784 &btrfs_ktype, parent, "%pU", fs_devs->fsid);
785 return error;
786}
787
788int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info)
789{
790 int error;
791 struct btrfs_fs_devices *fs_devs = fs_info->fs_devices;
792 struct kobject *fsid_kobj = &fs_devs->fsid_kobj;
793
794 btrfs_set_fs_info_ptr(fs_info);
795
796 error = btrfs_sysfs_add_device_link(fs_devs, NULL);
797 if (error)
798 return error;
799
800 error = sysfs_create_files(fsid_kobj, btrfs_attrs);
801 if (error) {
802 btrfs_sysfs_rm_device_link(fs_devs, NULL);
803 return error;
804 }
805
806 error = sysfs_create_group(fsid_kobj,
807 &btrfs_feature_attr_group);
808 if (error)
809 goto failure;
810
811 error = addrm_unknown_feature_attrs(fs_info, true);
812 if (error)
813 goto failure;
814
815 fs_info->space_info_kobj = kobject_create_and_add("allocation",
816 fsid_kobj);
817 if (!fs_info->space_info_kobj) {
818 error = -ENOMEM;
819 goto failure;
820 }
821
822 error = sysfs_create_files(fs_info->space_info_kobj, allocation_attrs);
823 if (error)
824 goto failure;
825
826 return 0;
827failure:
828 btrfs_sysfs_remove_mounted(fs_info);
829 return error;
830}
831
832
833/*
834 * Change per-fs features in /sys/fs/btrfs/UUID/features to match current
835 * values in superblock. Call after any changes to incompat/compat_ro flags
836 */
837void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info,
838 u64 bit, enum btrfs_feature_set set)
839{
840 struct btrfs_fs_devices *fs_devs;
841 struct kobject *fsid_kobj;
842 u64 features;
843 int ret;
844
845 if (!fs_info)
846 return;
847
848 features = get_features(fs_info, set);
849 ASSERT(bit & supported_feature_masks[set]);
850
851 fs_devs = fs_info->fs_devices;
852 fsid_kobj = &fs_devs->fsid_kobj;
853
854 if (!fsid_kobj->state_initialized)
855 return;
856
857 /*
858 * FIXME: this is too heavy to update just one value, ideally we'd like
859 * to use sysfs_update_group but some refactoring is needed first.
860 */
861 sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
862 ret = sysfs_create_group(fsid_kobj, &btrfs_feature_attr_group);
863}
864
865static int btrfs_init_debugfs(void)
866{
867#ifdef CONFIG_DEBUG_FS
868 btrfs_debugfs_root_dentry = debugfs_create_dir("btrfs", NULL);
869 if (!btrfs_debugfs_root_dentry)
870 return -ENOMEM;
871
872 /*
873 * Example code, how to export data through debugfs.
874 *
875 * file: /sys/kernel/debug/btrfs/test
876 * contents of: btrfs_debugfs_test
877 */
878#ifdef CONFIG_BTRFS_DEBUG
879 debugfs_create_u64("test", S_IRUGO | S_IWUSR, btrfs_debugfs_root_dentry,
880 &btrfs_debugfs_test);
881#endif
882
883#endif
884 return 0;
885}
886
887int __init btrfs_init_sysfs(void)
888{
889 int ret;
890
891 btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj);
892 if (!btrfs_kset)
893 return -ENOMEM;
894
895 ret = btrfs_init_debugfs();
896 if (ret)
897 goto out1;
898
899 init_feature_attrs();
900 ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
901 if (ret)
902 goto out2;
903
904 return 0;
905out2:
906 debugfs_remove_recursive(btrfs_debugfs_root_dentry);
907out1:
908 kset_unregister(btrfs_kset);
909
910 return ret;
911}
912
913void __cold btrfs_exit_sysfs(void)
914{
915 sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
916 kset_unregister(btrfs_kset);
917 debugfs_remove_recursive(btrfs_debugfs_root_dentry);
918}
919
1/*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19#include <linux/sched.h>
20#include <linux/slab.h>
21#include <linux/spinlock.h>
22#include <linux/completion.h>
23#include <linux/buffer_head.h>
24#include <linux/kobject.h>
25#include <linux/bug.h>
26#include <linux/genhd.h>
27#include <linux/debugfs.h>
28
29#include "ctree.h"
30#include "disk-io.h"
31#include "transaction.h"
32#include "sysfs.h"
33#include "volumes.h"
34
35static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj);
36
37static u64 get_features(struct btrfs_fs_info *fs_info,
38 enum btrfs_feature_set set)
39{
40 struct btrfs_super_block *disk_super = fs_info->super_copy;
41 if (set == FEAT_COMPAT)
42 return btrfs_super_compat_flags(disk_super);
43 else if (set == FEAT_COMPAT_RO)
44 return btrfs_super_compat_ro_flags(disk_super);
45 else
46 return btrfs_super_incompat_flags(disk_super);
47}
48
49static void set_features(struct btrfs_fs_info *fs_info,
50 enum btrfs_feature_set set, u64 features)
51{
52 struct btrfs_super_block *disk_super = fs_info->super_copy;
53 if (set == FEAT_COMPAT)
54 btrfs_set_super_compat_flags(disk_super, features);
55 else if (set == FEAT_COMPAT_RO)
56 btrfs_set_super_compat_ro_flags(disk_super, features);
57 else
58 btrfs_set_super_incompat_flags(disk_super, features);
59}
60
61static int can_modify_feature(struct btrfs_feature_attr *fa)
62{
63 int val = 0;
64 u64 set, clear;
65 switch (fa->feature_set) {
66 case FEAT_COMPAT:
67 set = BTRFS_FEATURE_COMPAT_SAFE_SET;
68 clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
69 break;
70 case FEAT_COMPAT_RO:
71 set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
72 clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
73 break;
74 case FEAT_INCOMPAT:
75 set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
76 clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
77 break;
78 default:
79 printk(KERN_WARNING "btrfs: sysfs: unknown feature set %d\n",
80 fa->feature_set);
81 return 0;
82 }
83
84 if (set & fa->feature_bit)
85 val |= 1;
86 if (clear & fa->feature_bit)
87 val |= 2;
88
89 return val;
90}
91
92static ssize_t btrfs_feature_attr_show(struct kobject *kobj,
93 struct kobj_attribute *a, char *buf)
94{
95 int val = 0;
96 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
97 struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
98 if (fs_info) {
99 u64 features = get_features(fs_info, fa->feature_set);
100 if (features & fa->feature_bit)
101 val = 1;
102 } else
103 val = can_modify_feature(fa);
104
105 return snprintf(buf, PAGE_SIZE, "%d\n", val);
106}
107
108static ssize_t btrfs_feature_attr_store(struct kobject *kobj,
109 struct kobj_attribute *a,
110 const char *buf, size_t count)
111{
112 struct btrfs_fs_info *fs_info;
113 struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
114 struct btrfs_trans_handle *trans;
115 u64 features, set, clear;
116 unsigned long val;
117 int ret;
118
119 fs_info = to_fs_info(kobj);
120 if (!fs_info)
121 return -EPERM;
122
123 ret = kstrtoul(skip_spaces(buf), 0, &val);
124 if (ret)
125 return ret;
126
127 if (fa->feature_set == FEAT_COMPAT) {
128 set = BTRFS_FEATURE_COMPAT_SAFE_SET;
129 clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
130 } else if (fa->feature_set == FEAT_COMPAT_RO) {
131 set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
132 clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
133 } else {
134 set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
135 clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
136 }
137
138 features = get_features(fs_info, fa->feature_set);
139
140 /* Nothing to do */
141 if ((val && (features & fa->feature_bit)) ||
142 (!val && !(features & fa->feature_bit)))
143 return count;
144
145 if ((val && !(set & fa->feature_bit)) ||
146 (!val && !(clear & fa->feature_bit))) {
147 btrfs_info(fs_info,
148 "%sabling feature %s on mounted fs is not supported.",
149 val ? "En" : "Dis", fa->kobj_attr.attr.name);
150 return -EPERM;
151 }
152
153 btrfs_info(fs_info, "%s %s feature flag",
154 val ? "Setting" : "Clearing", fa->kobj_attr.attr.name);
155
156 trans = btrfs_start_transaction(fs_info->fs_root, 0);
157 if (IS_ERR(trans))
158 return PTR_ERR(trans);
159
160 spin_lock(&fs_info->super_lock);
161 features = get_features(fs_info, fa->feature_set);
162 if (val)
163 features |= fa->feature_bit;
164 else
165 features &= ~fa->feature_bit;
166 set_features(fs_info, fa->feature_set, features);
167 spin_unlock(&fs_info->super_lock);
168
169 ret = btrfs_commit_transaction(trans, fs_info->fs_root);
170 if (ret)
171 return ret;
172
173 return count;
174}
175
176static umode_t btrfs_feature_visible(struct kobject *kobj,
177 struct attribute *attr, int unused)
178{
179 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
180 umode_t mode = attr->mode;
181
182 if (fs_info) {
183 struct btrfs_feature_attr *fa;
184 u64 features;
185
186 fa = attr_to_btrfs_feature_attr(attr);
187 features = get_features(fs_info, fa->feature_set);
188
189 if (can_modify_feature(fa))
190 mode |= S_IWUSR;
191 else if (!(features & fa->feature_bit))
192 mode = 0;
193 }
194
195 return mode;
196}
197
198BTRFS_FEAT_ATTR_INCOMPAT(mixed_backref, MIXED_BACKREF);
199BTRFS_FEAT_ATTR_INCOMPAT(default_subvol, DEFAULT_SUBVOL);
200BTRFS_FEAT_ATTR_INCOMPAT(mixed_groups, MIXED_GROUPS);
201BTRFS_FEAT_ATTR_INCOMPAT(compress_lzo, COMPRESS_LZO);
202BTRFS_FEAT_ATTR_INCOMPAT(big_metadata, BIG_METADATA);
203BTRFS_FEAT_ATTR_INCOMPAT(extended_iref, EXTENDED_IREF);
204BTRFS_FEAT_ATTR_INCOMPAT(raid56, RAID56);
205BTRFS_FEAT_ATTR_INCOMPAT(skinny_metadata, SKINNY_METADATA);
206BTRFS_FEAT_ATTR_INCOMPAT(no_holes, NO_HOLES);
207
208static struct attribute *btrfs_supported_feature_attrs[] = {
209 BTRFS_FEAT_ATTR_PTR(mixed_backref),
210 BTRFS_FEAT_ATTR_PTR(default_subvol),
211 BTRFS_FEAT_ATTR_PTR(mixed_groups),
212 BTRFS_FEAT_ATTR_PTR(compress_lzo),
213 BTRFS_FEAT_ATTR_PTR(big_metadata),
214 BTRFS_FEAT_ATTR_PTR(extended_iref),
215 BTRFS_FEAT_ATTR_PTR(raid56),
216 BTRFS_FEAT_ATTR_PTR(skinny_metadata),
217 BTRFS_FEAT_ATTR_PTR(no_holes),
218 NULL
219};
220
221static const struct attribute_group btrfs_feature_attr_group = {
222 .name = "features",
223 .is_visible = btrfs_feature_visible,
224 .attrs = btrfs_supported_feature_attrs,
225};
226
227static ssize_t btrfs_show_u64(u64 *value_ptr, spinlock_t *lock, char *buf)
228{
229 u64 val;
230 if (lock)
231 spin_lock(lock);
232 val = *value_ptr;
233 if (lock)
234 spin_unlock(lock);
235 return snprintf(buf, PAGE_SIZE, "%llu\n", val);
236}
237
238static ssize_t global_rsv_size_show(struct kobject *kobj,
239 struct kobj_attribute *ka, char *buf)
240{
241 struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
242 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
243 return btrfs_show_u64(&block_rsv->size, &block_rsv->lock, buf);
244}
245BTRFS_ATTR(global_rsv_size, 0444, global_rsv_size_show);
246
247static ssize_t global_rsv_reserved_show(struct kobject *kobj,
248 struct kobj_attribute *a, char *buf)
249{
250 struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
251 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
252 return btrfs_show_u64(&block_rsv->reserved, &block_rsv->lock, buf);
253}
254BTRFS_ATTR(global_rsv_reserved, 0444, global_rsv_reserved_show);
255
256#define to_space_info(_kobj) container_of(_kobj, struct btrfs_space_info, kobj)
257
258static ssize_t raid_bytes_show(struct kobject *kobj,
259 struct kobj_attribute *attr, char *buf);
260BTRFS_RAID_ATTR(total_bytes, raid_bytes_show);
261BTRFS_RAID_ATTR(used_bytes, raid_bytes_show);
262
263static ssize_t raid_bytes_show(struct kobject *kobj,
264 struct kobj_attribute *attr, char *buf)
265
266{
267 struct btrfs_space_info *sinfo = to_space_info(kobj->parent);
268 struct btrfs_block_group_cache *block_group;
269 int index = kobj - sinfo->block_group_kobjs;
270 u64 val = 0;
271
272 down_read(&sinfo->groups_sem);
273 list_for_each_entry(block_group, &sinfo->block_groups[index], list) {
274 if (&attr->attr == BTRFS_RAID_ATTR_PTR(total_bytes))
275 val += block_group->key.offset;
276 else
277 val += btrfs_block_group_used(&block_group->item);
278 }
279 up_read(&sinfo->groups_sem);
280 return snprintf(buf, PAGE_SIZE, "%llu\n", val);
281}
282
283static struct attribute *raid_attributes[] = {
284 BTRFS_RAID_ATTR_PTR(total_bytes),
285 BTRFS_RAID_ATTR_PTR(used_bytes),
286 NULL
287};
288
289static void release_raid_kobj(struct kobject *kobj)
290{
291 kobject_put(kobj->parent);
292}
293
294struct kobj_type btrfs_raid_ktype = {
295 .sysfs_ops = &kobj_sysfs_ops,
296 .release = release_raid_kobj,
297 .default_attrs = raid_attributes,
298};
299
300#define SPACE_INFO_ATTR(field) \
301static ssize_t btrfs_space_info_show_##field(struct kobject *kobj, \
302 struct kobj_attribute *a, \
303 char *buf) \
304{ \
305 struct btrfs_space_info *sinfo = to_space_info(kobj); \
306 return btrfs_show_u64(&sinfo->field, &sinfo->lock, buf); \
307} \
308BTRFS_ATTR(field, 0444, btrfs_space_info_show_##field)
309
310static ssize_t btrfs_space_info_show_total_bytes_pinned(struct kobject *kobj,
311 struct kobj_attribute *a,
312 char *buf)
313{
314 struct btrfs_space_info *sinfo = to_space_info(kobj);
315 s64 val = percpu_counter_sum(&sinfo->total_bytes_pinned);
316 return snprintf(buf, PAGE_SIZE, "%lld\n", val);
317}
318
319SPACE_INFO_ATTR(flags);
320SPACE_INFO_ATTR(total_bytes);
321SPACE_INFO_ATTR(bytes_used);
322SPACE_INFO_ATTR(bytes_pinned);
323SPACE_INFO_ATTR(bytes_reserved);
324SPACE_INFO_ATTR(bytes_may_use);
325SPACE_INFO_ATTR(disk_used);
326SPACE_INFO_ATTR(disk_total);
327BTRFS_ATTR(total_bytes_pinned, 0444, btrfs_space_info_show_total_bytes_pinned);
328
329static struct attribute *space_info_attrs[] = {
330 BTRFS_ATTR_PTR(flags),
331 BTRFS_ATTR_PTR(total_bytes),
332 BTRFS_ATTR_PTR(bytes_used),
333 BTRFS_ATTR_PTR(bytes_pinned),
334 BTRFS_ATTR_PTR(bytes_reserved),
335 BTRFS_ATTR_PTR(bytes_may_use),
336 BTRFS_ATTR_PTR(disk_used),
337 BTRFS_ATTR_PTR(disk_total),
338 BTRFS_ATTR_PTR(total_bytes_pinned),
339 NULL,
340};
341
342static void space_info_release(struct kobject *kobj)
343{
344 struct btrfs_space_info *sinfo = to_space_info(kobj);
345 percpu_counter_destroy(&sinfo->total_bytes_pinned);
346 kfree(sinfo);
347}
348
349struct kobj_type space_info_ktype = {
350 .sysfs_ops = &kobj_sysfs_ops,
351 .release = space_info_release,
352 .default_attrs = space_info_attrs,
353};
354
355static const struct attribute *allocation_attrs[] = {
356 BTRFS_ATTR_PTR(global_rsv_reserved),
357 BTRFS_ATTR_PTR(global_rsv_size),
358 NULL,
359};
360
361static ssize_t btrfs_label_show(struct kobject *kobj,
362 struct kobj_attribute *a, char *buf)
363{
364 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
365 return snprintf(buf, PAGE_SIZE, "%s\n", fs_info->super_copy->label);
366}
367
368static ssize_t btrfs_label_store(struct kobject *kobj,
369 struct kobj_attribute *a,
370 const char *buf, size_t len)
371{
372 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
373 struct btrfs_trans_handle *trans;
374 struct btrfs_root *root = fs_info->fs_root;
375 int ret;
376
377 if (len >= BTRFS_LABEL_SIZE) {
378 pr_err("BTRFS: unable to set label with more than %d bytes\n",
379 BTRFS_LABEL_SIZE - 1);
380 return -EINVAL;
381 }
382
383 trans = btrfs_start_transaction(root, 0);
384 if (IS_ERR(trans))
385 return PTR_ERR(trans);
386
387 spin_lock(&root->fs_info->super_lock);
388 strcpy(fs_info->super_copy->label, buf);
389 spin_unlock(&root->fs_info->super_lock);
390 ret = btrfs_commit_transaction(trans, root);
391
392 if (!ret)
393 return len;
394
395 return ret;
396}
397BTRFS_ATTR_RW(label, 0644, btrfs_label_show, btrfs_label_store);
398
399static struct attribute *btrfs_attrs[] = {
400 BTRFS_ATTR_PTR(label),
401 NULL,
402};
403
404static void btrfs_release_super_kobj(struct kobject *kobj)
405{
406 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
407 complete(&fs_info->kobj_unregister);
408}
409
410static struct kobj_type btrfs_ktype = {
411 .sysfs_ops = &kobj_sysfs_ops,
412 .release = btrfs_release_super_kobj,
413 .default_attrs = btrfs_attrs,
414};
415
416static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)
417{
418 if (kobj->ktype != &btrfs_ktype)
419 return NULL;
420 return container_of(kobj, struct btrfs_fs_info, super_kobj);
421}
422
423#define NUM_FEATURE_BITS 64
424static char btrfs_unknown_feature_names[3][NUM_FEATURE_BITS][13];
425static struct btrfs_feature_attr btrfs_feature_attrs[3][NUM_FEATURE_BITS];
426
427static u64 supported_feature_masks[3] = {
428 [FEAT_COMPAT] = BTRFS_FEATURE_COMPAT_SUPP,
429 [FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP,
430 [FEAT_INCOMPAT] = BTRFS_FEATURE_INCOMPAT_SUPP,
431};
432
433static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add)
434{
435 int set;
436
437 for (set = 0; set < FEAT_MAX; set++) {
438 int i;
439 struct attribute *attrs[2];
440 struct attribute_group agroup = {
441 .name = "features",
442 .attrs = attrs,
443 };
444 u64 features = get_features(fs_info, set);
445 features &= ~supported_feature_masks[set];
446
447 if (!features)
448 continue;
449
450 attrs[1] = NULL;
451 for (i = 0; i < NUM_FEATURE_BITS; i++) {
452 struct btrfs_feature_attr *fa;
453
454 if (!(features & (1ULL << i)))
455 continue;
456
457 fa = &btrfs_feature_attrs[set][i];
458 attrs[0] = &fa->kobj_attr.attr;
459 if (add) {
460 int ret;
461 ret = sysfs_merge_group(&fs_info->super_kobj,
462 &agroup);
463 if (ret)
464 return ret;
465 } else
466 sysfs_unmerge_group(&fs_info->super_kobj,
467 &agroup);
468 }
469
470 }
471 return 0;
472}
473
474static void __btrfs_sysfs_remove_one(struct btrfs_fs_info *fs_info)
475{
476 kobject_del(&fs_info->super_kobj);
477 kobject_put(&fs_info->super_kobj);
478 wait_for_completion(&fs_info->kobj_unregister);
479}
480
481void btrfs_sysfs_remove_one(struct btrfs_fs_info *fs_info)
482{
483 if (fs_info->space_info_kobj) {
484 sysfs_remove_files(fs_info->space_info_kobj, allocation_attrs);
485 kobject_del(fs_info->space_info_kobj);
486 kobject_put(fs_info->space_info_kobj);
487 }
488 kobject_del(fs_info->device_dir_kobj);
489 kobject_put(fs_info->device_dir_kobj);
490 addrm_unknown_feature_attrs(fs_info, false);
491 sysfs_remove_group(&fs_info->super_kobj, &btrfs_feature_attr_group);
492 __btrfs_sysfs_remove_one(fs_info);
493}
494
495const char * const btrfs_feature_set_names[3] = {
496 [FEAT_COMPAT] = "compat",
497 [FEAT_COMPAT_RO] = "compat_ro",
498 [FEAT_INCOMPAT] = "incompat",
499};
500
501char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags)
502{
503 size_t bufsize = 4096; /* safe max, 64 names * 64 bytes */
504 int len = 0;
505 int i;
506 char *str;
507
508 str = kmalloc(bufsize, GFP_KERNEL);
509 if (!str)
510 return str;
511
512 for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
513 const char *name;
514
515 if (!(flags & (1ULL << i)))
516 continue;
517
518 name = btrfs_feature_attrs[set][i].kobj_attr.attr.name;
519 len += snprintf(str + len, bufsize - len, "%s%s",
520 len ? "," : "", name);
521 }
522
523 return str;
524}
525
526static void init_feature_attrs(void)
527{
528 struct btrfs_feature_attr *fa;
529 int set, i;
530
531 BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names) !=
532 ARRAY_SIZE(btrfs_feature_attrs));
533 BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names[0]) !=
534 ARRAY_SIZE(btrfs_feature_attrs[0]));
535
536 memset(btrfs_feature_attrs, 0, sizeof(btrfs_feature_attrs));
537 memset(btrfs_unknown_feature_names, 0,
538 sizeof(btrfs_unknown_feature_names));
539
540 for (i = 0; btrfs_supported_feature_attrs[i]; i++) {
541 struct btrfs_feature_attr *sfa;
542 struct attribute *a = btrfs_supported_feature_attrs[i];
543 int bit;
544 sfa = attr_to_btrfs_feature_attr(a);
545 bit = ilog2(sfa->feature_bit);
546 fa = &btrfs_feature_attrs[sfa->feature_set][bit];
547
548 fa->kobj_attr.attr.name = sfa->kobj_attr.attr.name;
549 }
550
551 for (set = 0; set < FEAT_MAX; set++) {
552 for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
553 char *name = btrfs_unknown_feature_names[set][i];
554 fa = &btrfs_feature_attrs[set][i];
555
556 if (fa->kobj_attr.attr.name)
557 continue;
558
559 snprintf(name, 13, "%s:%u",
560 btrfs_feature_set_names[set], i);
561
562 fa->kobj_attr.attr.name = name;
563 fa->kobj_attr.attr.mode = S_IRUGO;
564 fa->feature_set = set;
565 fa->feature_bit = 1ULL << i;
566 }
567 }
568}
569
570static int add_device_membership(struct btrfs_fs_info *fs_info)
571{
572 int error = 0;
573 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
574 struct btrfs_device *dev;
575
576 fs_info->device_dir_kobj = kobject_create_and_add("devices",
577 &fs_info->super_kobj);
578 if (!fs_info->device_dir_kobj)
579 return -ENOMEM;
580
581 list_for_each_entry(dev, &fs_devices->devices, dev_list) {
582 struct hd_struct *disk;
583 struct kobject *disk_kobj;
584
585 if (!dev->bdev)
586 continue;
587
588 disk = dev->bdev->bd_part;
589 disk_kobj = &part_to_dev(disk)->kobj;
590
591 error = sysfs_create_link(fs_info->device_dir_kobj,
592 disk_kobj, disk_kobj->name);
593 if (error)
594 break;
595 }
596
597 return error;
598}
599
600/* /sys/fs/btrfs/ entry */
601static struct kset *btrfs_kset;
602
603/* /sys/kernel/debug/btrfs */
604static struct dentry *btrfs_debugfs_root_dentry;
605
606/* Debugging tunables and exported data */
607u64 btrfs_debugfs_test;
608
609int btrfs_sysfs_add_one(struct btrfs_fs_info *fs_info)
610{
611 int error;
612
613 init_completion(&fs_info->kobj_unregister);
614 fs_info->super_kobj.kset = btrfs_kset;
615 error = kobject_init_and_add(&fs_info->super_kobj, &btrfs_ktype, NULL,
616 "%pU", fs_info->fsid);
617 if (error)
618 return error;
619
620 error = sysfs_create_group(&fs_info->super_kobj,
621 &btrfs_feature_attr_group);
622 if (error) {
623 __btrfs_sysfs_remove_one(fs_info);
624 return error;
625 }
626
627 error = addrm_unknown_feature_attrs(fs_info, true);
628 if (error)
629 goto failure;
630
631 error = add_device_membership(fs_info);
632 if (error)
633 goto failure;
634
635 fs_info->space_info_kobj = kobject_create_and_add("allocation",
636 &fs_info->super_kobj);
637 if (!fs_info->space_info_kobj) {
638 error = -ENOMEM;
639 goto failure;
640 }
641
642 error = sysfs_create_files(fs_info->space_info_kobj, allocation_attrs);
643 if (error)
644 goto failure;
645
646 return 0;
647failure:
648 btrfs_sysfs_remove_one(fs_info);
649 return error;
650}
651
652static int btrfs_init_debugfs(void)
653{
654#ifdef CONFIG_DEBUG_FS
655 btrfs_debugfs_root_dentry = debugfs_create_dir("btrfs", NULL);
656 if (!btrfs_debugfs_root_dentry)
657 return -ENOMEM;
658
659 debugfs_create_u64("test", S_IRUGO | S_IWUGO, btrfs_debugfs_root_dentry,
660 &btrfs_debugfs_test);
661#endif
662 return 0;
663}
664
665int btrfs_init_sysfs(void)
666{
667 int ret;
668
669 btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj);
670 if (!btrfs_kset)
671 return -ENOMEM;
672
673 ret = btrfs_init_debugfs();
674 if (ret)
675 return ret;
676
677 init_feature_attrs();
678 ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
679
680 return ret;
681}
682
683void btrfs_exit_sysfs(void)
684{
685 sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
686 kset_unregister(btrfs_kset);
687 debugfs_remove_recursive(btrfs_debugfs_root_dentry);
688}
689