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