tools headers UAPI: Sync linux/prctl.h with the kernel sources
[linux-2.6-microblaze.git] / fs / nilfs2 / sysfs.c
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * sysfs.c - sysfs support implementation.
4  *
5  * Copyright (C) 2005-2014 Nippon Telegraph and Telephone Corporation.
6  * Copyright (C) 2014 HGST, Inc., a Western Digital Company.
7  *
8  * Written by Vyacheslav Dubeyko <Vyacheslav.Dubeyko@hgst.com>
9  */
10
11 #include <linux/kobject.h>
12
13 #include "nilfs.h"
14 #include "mdt.h"
15 #include "sufile.h"
16 #include "cpfile.h"
17 #include "sysfs.h"
18
19 /* /sys/fs/<nilfs>/ */
20 static struct kset *nilfs_kset;
21
22 #define NILFS_SHOW_TIME(time_t_val, buf) ({ \
23                 struct tm res; \
24                 int count = 0; \
25                 time64_to_tm(time_t_val, 0, &res); \
26                 res.tm_year += 1900; \
27                 res.tm_mon += 1; \
28                 count = scnprintf(buf, PAGE_SIZE, \
29                                     "%ld-%.2d-%.2d %.2d:%.2d:%.2d\n", \
30                                     res.tm_year, res.tm_mon, res.tm_mday, \
31                                     res.tm_hour, res.tm_min, res.tm_sec);\
32                 count; \
33 })
34
35 #define NILFS_DEV_INT_GROUP_OPS(name, parent_name) \
36 static ssize_t nilfs_##name##_attr_show(struct kobject *kobj, \
37                                         struct attribute *attr, char *buf) \
38 { \
39         struct the_nilfs *nilfs = container_of(kobj->parent, \
40                                                 struct the_nilfs, \
41                                                 ns_##parent_name##_kobj); \
42         struct nilfs_##name##_attr *a = container_of(attr, \
43                                                 struct nilfs_##name##_attr, \
44                                                 attr); \
45         return a->show ? a->show(a, nilfs, buf) : 0; \
46 } \
47 static ssize_t nilfs_##name##_attr_store(struct kobject *kobj, \
48                                          struct attribute *attr, \
49                                          const char *buf, size_t len) \
50 { \
51         struct the_nilfs *nilfs = container_of(kobj->parent, \
52                                                 struct the_nilfs, \
53                                                 ns_##parent_name##_kobj); \
54         struct nilfs_##name##_attr *a = container_of(attr, \
55                                                 struct nilfs_##name##_attr, \
56                                                 attr); \
57         return a->store ? a->store(a, nilfs, buf, len) : 0; \
58 } \
59 static const struct sysfs_ops nilfs_##name##_attr_ops = { \
60         .show   = nilfs_##name##_attr_show, \
61         .store  = nilfs_##name##_attr_store, \
62 }
63
64 #define NILFS_DEV_INT_GROUP_TYPE(name, parent_name) \
65 static void nilfs_##name##_attr_release(struct kobject *kobj) \
66 { \
67         struct nilfs_sysfs_##parent_name##_subgroups *subgroups; \
68         struct the_nilfs *nilfs = container_of(kobj->parent, \
69                                                 struct the_nilfs, \
70                                                 ns_##parent_name##_kobj); \
71         subgroups = nilfs->ns_##parent_name##_subgroups; \
72         complete(&subgroups->sg_##name##_kobj_unregister); \
73 } \
74 static struct kobj_type nilfs_##name##_ktype = { \
75         .default_attrs  = nilfs_##name##_attrs, \
76         .sysfs_ops      = &nilfs_##name##_attr_ops, \
77         .release        = nilfs_##name##_attr_release, \
78 }
79
80 #define NILFS_DEV_INT_GROUP_FNS(name, parent_name) \
81 static int nilfs_sysfs_create_##name##_group(struct the_nilfs *nilfs) \
82 { \
83         struct kobject *parent; \
84         struct kobject *kobj; \
85         struct completion *kobj_unregister; \
86         struct nilfs_sysfs_##parent_name##_subgroups *subgroups; \
87         int err; \
88         subgroups = nilfs->ns_##parent_name##_subgroups; \
89         kobj = &subgroups->sg_##name##_kobj; \
90         kobj_unregister = &subgroups->sg_##name##_kobj_unregister; \
91         parent = &nilfs->ns_##parent_name##_kobj; \
92         kobj->kset = nilfs_kset; \
93         init_completion(kobj_unregister); \
94         err = kobject_init_and_add(kobj, &nilfs_##name##_ktype, parent, \
95                                     #name); \
96         if (err) \
97                 return err; \
98         return 0; \
99 } \
100 static void nilfs_sysfs_delete_##name##_group(struct the_nilfs *nilfs) \
101 { \
102         kobject_del(&nilfs->ns_##parent_name##_subgroups->sg_##name##_kobj); \
103 }
104
105 /************************************************************************
106  *                        NILFS snapshot attrs                          *
107  ************************************************************************/
108
109 static ssize_t
110 nilfs_snapshot_inodes_count_show(struct nilfs_snapshot_attr *attr,
111                                  struct nilfs_root *root, char *buf)
112 {
113         return snprintf(buf, PAGE_SIZE, "%llu\n",
114                         (unsigned long long)atomic64_read(&root->inodes_count));
115 }
116
117 static ssize_t
118 nilfs_snapshot_blocks_count_show(struct nilfs_snapshot_attr *attr,
119                                  struct nilfs_root *root, char *buf)
120 {
121         return snprintf(buf, PAGE_SIZE, "%llu\n",
122                         (unsigned long long)atomic64_read(&root->blocks_count));
123 }
124
125 static const char snapshot_readme_str[] =
126         "The group contains details about mounted snapshot.\n\n"
127         "(1) inodes_count\n\tshow number of inodes for snapshot.\n\n"
128         "(2) blocks_count\n\tshow number of blocks for snapshot.\n\n";
129
130 static ssize_t
131 nilfs_snapshot_README_show(struct nilfs_snapshot_attr *attr,
132                             struct nilfs_root *root, char *buf)
133 {
134         return snprintf(buf, PAGE_SIZE, snapshot_readme_str);
135 }
136
137 NILFS_SNAPSHOT_RO_ATTR(inodes_count);
138 NILFS_SNAPSHOT_RO_ATTR(blocks_count);
139 NILFS_SNAPSHOT_RO_ATTR(README);
140
141 static struct attribute *nilfs_snapshot_attrs[] = {
142         NILFS_SNAPSHOT_ATTR_LIST(inodes_count),
143         NILFS_SNAPSHOT_ATTR_LIST(blocks_count),
144         NILFS_SNAPSHOT_ATTR_LIST(README),
145         NULL,
146 };
147
148 static ssize_t nilfs_snapshot_attr_show(struct kobject *kobj,
149                                         struct attribute *attr, char *buf)
150 {
151         struct nilfs_root *root =
152                         container_of(kobj, struct nilfs_root, snapshot_kobj);
153         struct nilfs_snapshot_attr *a =
154                         container_of(attr, struct nilfs_snapshot_attr, attr);
155
156         return a->show ? a->show(a, root, buf) : 0;
157 }
158
159 static ssize_t nilfs_snapshot_attr_store(struct kobject *kobj,
160                                          struct attribute *attr,
161                                          const char *buf, size_t len)
162 {
163         struct nilfs_root *root =
164                         container_of(kobj, struct nilfs_root, snapshot_kobj);
165         struct nilfs_snapshot_attr *a =
166                         container_of(attr, struct nilfs_snapshot_attr, attr);
167
168         return a->store ? a->store(a, root, buf, len) : 0;
169 }
170
171 static void nilfs_snapshot_attr_release(struct kobject *kobj)
172 {
173         struct nilfs_root *root = container_of(kobj, struct nilfs_root,
174                                                 snapshot_kobj);
175         complete(&root->snapshot_kobj_unregister);
176 }
177
178 static const struct sysfs_ops nilfs_snapshot_attr_ops = {
179         .show   = nilfs_snapshot_attr_show,
180         .store  = nilfs_snapshot_attr_store,
181 };
182
183 static struct kobj_type nilfs_snapshot_ktype = {
184         .default_attrs  = nilfs_snapshot_attrs,
185         .sysfs_ops      = &nilfs_snapshot_attr_ops,
186         .release        = nilfs_snapshot_attr_release,
187 };
188
189 int nilfs_sysfs_create_snapshot_group(struct nilfs_root *root)
190 {
191         struct the_nilfs *nilfs;
192         struct kobject *parent;
193         int err;
194
195         nilfs = root->nilfs;
196         parent = &nilfs->ns_dev_subgroups->sg_mounted_snapshots_kobj;
197         root->snapshot_kobj.kset = nilfs_kset;
198         init_completion(&root->snapshot_kobj_unregister);
199
200         if (root->cno == NILFS_CPTREE_CURRENT_CNO) {
201                 err = kobject_init_and_add(&root->snapshot_kobj,
202                                             &nilfs_snapshot_ktype,
203                                             &nilfs->ns_dev_kobj,
204                                             "current_checkpoint");
205         } else {
206                 err = kobject_init_and_add(&root->snapshot_kobj,
207                                             &nilfs_snapshot_ktype,
208                                             parent,
209                                             "%llu", root->cno);
210         }
211
212         if (err)
213                 return err;
214
215         return 0;
216 }
217
218 void nilfs_sysfs_delete_snapshot_group(struct nilfs_root *root)
219 {
220         kobject_del(&root->snapshot_kobj);
221 }
222
223 /************************************************************************
224  *                    NILFS mounted snapshots attrs                     *
225  ************************************************************************/
226
227 static const char mounted_snapshots_readme_str[] =
228         "The mounted_snapshots group contains group for\n"
229         "every mounted snapshot.\n";
230
231 static ssize_t
232 nilfs_mounted_snapshots_README_show(struct nilfs_mounted_snapshots_attr *attr,
233                                     struct the_nilfs *nilfs, char *buf)
234 {
235         return snprintf(buf, PAGE_SIZE, mounted_snapshots_readme_str);
236 }
237
238 NILFS_MOUNTED_SNAPSHOTS_RO_ATTR(README);
239
240 static struct attribute *nilfs_mounted_snapshots_attrs[] = {
241         NILFS_MOUNTED_SNAPSHOTS_ATTR_LIST(README),
242         NULL,
243 };
244
245 NILFS_DEV_INT_GROUP_OPS(mounted_snapshots, dev);
246 NILFS_DEV_INT_GROUP_TYPE(mounted_snapshots, dev);
247 NILFS_DEV_INT_GROUP_FNS(mounted_snapshots, dev);
248
249 /************************************************************************
250  *                      NILFS checkpoints attrs                         *
251  ************************************************************************/
252
253 static ssize_t
254 nilfs_checkpoints_checkpoints_number_show(struct nilfs_checkpoints_attr *attr,
255                                             struct the_nilfs *nilfs,
256                                             char *buf)
257 {
258         __u64 ncheckpoints;
259         struct nilfs_cpstat cpstat;
260         int err;
261
262         down_read(&nilfs->ns_segctor_sem);
263         err = nilfs_cpfile_get_stat(nilfs->ns_cpfile, &cpstat);
264         up_read(&nilfs->ns_segctor_sem);
265         if (err < 0) {
266                 nilfs_err(nilfs->ns_sb, "unable to get checkpoint stat: err=%d",
267                           err);
268                 return err;
269         }
270
271         ncheckpoints = cpstat.cs_ncps;
272
273         return snprintf(buf, PAGE_SIZE, "%llu\n", ncheckpoints);
274 }
275
276 static ssize_t
277 nilfs_checkpoints_snapshots_number_show(struct nilfs_checkpoints_attr *attr,
278                                         struct the_nilfs *nilfs,
279                                         char *buf)
280 {
281         __u64 nsnapshots;
282         struct nilfs_cpstat cpstat;
283         int err;
284
285         down_read(&nilfs->ns_segctor_sem);
286         err = nilfs_cpfile_get_stat(nilfs->ns_cpfile, &cpstat);
287         up_read(&nilfs->ns_segctor_sem);
288         if (err < 0) {
289                 nilfs_err(nilfs->ns_sb, "unable to get checkpoint stat: err=%d",
290                           err);
291                 return err;
292         }
293
294         nsnapshots = cpstat.cs_nsss;
295
296         return snprintf(buf, PAGE_SIZE, "%llu\n", nsnapshots);
297 }
298
299 static ssize_t
300 nilfs_checkpoints_last_seg_checkpoint_show(struct nilfs_checkpoints_attr *attr,
301                                             struct the_nilfs *nilfs,
302                                             char *buf)
303 {
304         __u64 last_cno;
305
306         spin_lock(&nilfs->ns_last_segment_lock);
307         last_cno = nilfs->ns_last_cno;
308         spin_unlock(&nilfs->ns_last_segment_lock);
309
310         return snprintf(buf, PAGE_SIZE, "%llu\n", last_cno);
311 }
312
313 static ssize_t
314 nilfs_checkpoints_next_checkpoint_show(struct nilfs_checkpoints_attr *attr,
315                                         struct the_nilfs *nilfs,
316                                         char *buf)
317 {
318         __u64 cno;
319
320         down_read(&nilfs->ns_segctor_sem);
321         cno = nilfs->ns_cno;
322         up_read(&nilfs->ns_segctor_sem);
323
324         return snprintf(buf, PAGE_SIZE, "%llu\n", cno);
325 }
326
327 static const char checkpoints_readme_str[] =
328         "The checkpoints group contains attributes that describe\n"
329         "details about volume's checkpoints.\n\n"
330         "(1) checkpoints_number\n\tshow number of checkpoints on volume.\n\n"
331         "(2) snapshots_number\n\tshow number of snapshots on volume.\n\n"
332         "(3) last_seg_checkpoint\n"
333         "\tshow checkpoint number of the latest segment.\n\n"
334         "(4) next_checkpoint\n\tshow next checkpoint number.\n\n";
335
336 static ssize_t
337 nilfs_checkpoints_README_show(struct nilfs_checkpoints_attr *attr,
338                                 struct the_nilfs *nilfs, char *buf)
339 {
340         return snprintf(buf, PAGE_SIZE, checkpoints_readme_str);
341 }
342
343 NILFS_CHECKPOINTS_RO_ATTR(checkpoints_number);
344 NILFS_CHECKPOINTS_RO_ATTR(snapshots_number);
345 NILFS_CHECKPOINTS_RO_ATTR(last_seg_checkpoint);
346 NILFS_CHECKPOINTS_RO_ATTR(next_checkpoint);
347 NILFS_CHECKPOINTS_RO_ATTR(README);
348
349 static struct attribute *nilfs_checkpoints_attrs[] = {
350         NILFS_CHECKPOINTS_ATTR_LIST(checkpoints_number),
351         NILFS_CHECKPOINTS_ATTR_LIST(snapshots_number),
352         NILFS_CHECKPOINTS_ATTR_LIST(last_seg_checkpoint),
353         NILFS_CHECKPOINTS_ATTR_LIST(next_checkpoint),
354         NILFS_CHECKPOINTS_ATTR_LIST(README),
355         NULL,
356 };
357
358 NILFS_DEV_INT_GROUP_OPS(checkpoints, dev);
359 NILFS_DEV_INT_GROUP_TYPE(checkpoints, dev);
360 NILFS_DEV_INT_GROUP_FNS(checkpoints, dev);
361
362 /************************************************************************
363  *                        NILFS segments attrs                          *
364  ************************************************************************/
365
366 static ssize_t
367 nilfs_segments_segments_number_show(struct nilfs_segments_attr *attr,
368                                      struct the_nilfs *nilfs,
369                                      char *buf)
370 {
371         return snprintf(buf, PAGE_SIZE, "%lu\n", nilfs->ns_nsegments);
372 }
373
374 static ssize_t
375 nilfs_segments_blocks_per_segment_show(struct nilfs_segments_attr *attr,
376                                         struct the_nilfs *nilfs,
377                                         char *buf)
378 {
379         return snprintf(buf, PAGE_SIZE, "%lu\n", nilfs->ns_blocks_per_segment);
380 }
381
382 static ssize_t
383 nilfs_segments_clean_segments_show(struct nilfs_segments_attr *attr,
384                                     struct the_nilfs *nilfs,
385                                     char *buf)
386 {
387         unsigned long ncleansegs;
388
389         down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
390         ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile);
391         up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
392
393         return snprintf(buf, PAGE_SIZE, "%lu\n", ncleansegs);
394 }
395
396 static ssize_t
397 nilfs_segments_dirty_segments_show(struct nilfs_segments_attr *attr,
398                                     struct the_nilfs *nilfs,
399                                     char *buf)
400 {
401         struct nilfs_sustat sustat;
402         int err;
403
404         down_read(&nilfs->ns_segctor_sem);
405         err = nilfs_sufile_get_stat(nilfs->ns_sufile, &sustat);
406         up_read(&nilfs->ns_segctor_sem);
407         if (err < 0) {
408                 nilfs_err(nilfs->ns_sb, "unable to get segment stat: err=%d",
409                           err);
410                 return err;
411         }
412
413         return snprintf(buf, PAGE_SIZE, "%llu\n", sustat.ss_ndirtysegs);
414 }
415
416 static const char segments_readme_str[] =
417         "The segments group contains attributes that describe\n"
418         "details about volume's segments.\n\n"
419         "(1) segments_number\n\tshow number of segments on volume.\n\n"
420         "(2) blocks_per_segment\n\tshow number of blocks in segment.\n\n"
421         "(3) clean_segments\n\tshow count of clean segments.\n\n"
422         "(4) dirty_segments\n\tshow count of dirty segments.\n\n";
423
424 static ssize_t
425 nilfs_segments_README_show(struct nilfs_segments_attr *attr,
426                             struct the_nilfs *nilfs,
427                             char *buf)
428 {
429         return snprintf(buf, PAGE_SIZE, segments_readme_str);
430 }
431
432 NILFS_SEGMENTS_RO_ATTR(segments_number);
433 NILFS_SEGMENTS_RO_ATTR(blocks_per_segment);
434 NILFS_SEGMENTS_RO_ATTR(clean_segments);
435 NILFS_SEGMENTS_RO_ATTR(dirty_segments);
436 NILFS_SEGMENTS_RO_ATTR(README);
437
438 static struct attribute *nilfs_segments_attrs[] = {
439         NILFS_SEGMENTS_ATTR_LIST(segments_number),
440         NILFS_SEGMENTS_ATTR_LIST(blocks_per_segment),
441         NILFS_SEGMENTS_ATTR_LIST(clean_segments),
442         NILFS_SEGMENTS_ATTR_LIST(dirty_segments),
443         NILFS_SEGMENTS_ATTR_LIST(README),
444         NULL,
445 };
446
447 NILFS_DEV_INT_GROUP_OPS(segments, dev);
448 NILFS_DEV_INT_GROUP_TYPE(segments, dev);
449 NILFS_DEV_INT_GROUP_FNS(segments, dev);
450
451 /************************************************************************
452  *                        NILFS segctor attrs                           *
453  ************************************************************************/
454
455 static ssize_t
456 nilfs_segctor_last_pseg_block_show(struct nilfs_segctor_attr *attr,
457                                     struct the_nilfs *nilfs,
458                                     char *buf)
459 {
460         sector_t last_pseg;
461
462         spin_lock(&nilfs->ns_last_segment_lock);
463         last_pseg = nilfs->ns_last_pseg;
464         spin_unlock(&nilfs->ns_last_segment_lock);
465
466         return snprintf(buf, PAGE_SIZE, "%llu\n",
467                         (unsigned long long)last_pseg);
468 }
469
470 static ssize_t
471 nilfs_segctor_last_seg_sequence_show(struct nilfs_segctor_attr *attr,
472                                         struct the_nilfs *nilfs,
473                                         char *buf)
474 {
475         u64 last_seq;
476
477         spin_lock(&nilfs->ns_last_segment_lock);
478         last_seq = nilfs->ns_last_seq;
479         spin_unlock(&nilfs->ns_last_segment_lock);
480
481         return snprintf(buf, PAGE_SIZE, "%llu\n", last_seq);
482 }
483
484 static ssize_t
485 nilfs_segctor_last_seg_checkpoint_show(struct nilfs_segctor_attr *attr,
486                                         struct the_nilfs *nilfs,
487                                         char *buf)
488 {
489         __u64 last_cno;
490
491         spin_lock(&nilfs->ns_last_segment_lock);
492         last_cno = nilfs->ns_last_cno;
493         spin_unlock(&nilfs->ns_last_segment_lock);
494
495         return snprintf(buf, PAGE_SIZE, "%llu\n", last_cno);
496 }
497
498 static ssize_t
499 nilfs_segctor_current_seg_sequence_show(struct nilfs_segctor_attr *attr,
500                                         struct the_nilfs *nilfs,
501                                         char *buf)
502 {
503         u64 seg_seq;
504
505         down_read(&nilfs->ns_segctor_sem);
506         seg_seq = nilfs->ns_seg_seq;
507         up_read(&nilfs->ns_segctor_sem);
508
509         return snprintf(buf, PAGE_SIZE, "%llu\n", seg_seq);
510 }
511
512 static ssize_t
513 nilfs_segctor_current_last_full_seg_show(struct nilfs_segctor_attr *attr,
514                                          struct the_nilfs *nilfs,
515                                          char *buf)
516 {
517         __u64 segnum;
518
519         down_read(&nilfs->ns_segctor_sem);
520         segnum = nilfs->ns_segnum;
521         up_read(&nilfs->ns_segctor_sem);
522
523         return snprintf(buf, PAGE_SIZE, "%llu\n", segnum);
524 }
525
526 static ssize_t
527 nilfs_segctor_next_full_seg_show(struct nilfs_segctor_attr *attr,
528                                  struct the_nilfs *nilfs,
529                                  char *buf)
530 {
531         __u64 nextnum;
532
533         down_read(&nilfs->ns_segctor_sem);
534         nextnum = nilfs->ns_nextnum;
535         up_read(&nilfs->ns_segctor_sem);
536
537         return snprintf(buf, PAGE_SIZE, "%llu\n", nextnum);
538 }
539
540 static ssize_t
541 nilfs_segctor_next_pseg_offset_show(struct nilfs_segctor_attr *attr,
542                                         struct the_nilfs *nilfs,
543                                         char *buf)
544 {
545         unsigned long pseg_offset;
546
547         down_read(&nilfs->ns_segctor_sem);
548         pseg_offset = nilfs->ns_pseg_offset;
549         up_read(&nilfs->ns_segctor_sem);
550
551         return snprintf(buf, PAGE_SIZE, "%lu\n", pseg_offset);
552 }
553
554 static ssize_t
555 nilfs_segctor_next_checkpoint_show(struct nilfs_segctor_attr *attr,
556                                         struct the_nilfs *nilfs,
557                                         char *buf)
558 {
559         __u64 cno;
560
561         down_read(&nilfs->ns_segctor_sem);
562         cno = nilfs->ns_cno;
563         up_read(&nilfs->ns_segctor_sem);
564
565         return snprintf(buf, PAGE_SIZE, "%llu\n", cno);
566 }
567
568 static ssize_t
569 nilfs_segctor_last_seg_write_time_show(struct nilfs_segctor_attr *attr,
570                                         struct the_nilfs *nilfs,
571                                         char *buf)
572 {
573         time64_t ctime;
574
575         down_read(&nilfs->ns_segctor_sem);
576         ctime = nilfs->ns_ctime;
577         up_read(&nilfs->ns_segctor_sem);
578
579         return NILFS_SHOW_TIME(ctime, buf);
580 }
581
582 static ssize_t
583 nilfs_segctor_last_seg_write_time_secs_show(struct nilfs_segctor_attr *attr,
584                                             struct the_nilfs *nilfs,
585                                             char *buf)
586 {
587         time64_t ctime;
588
589         down_read(&nilfs->ns_segctor_sem);
590         ctime = nilfs->ns_ctime;
591         up_read(&nilfs->ns_segctor_sem);
592
593         return snprintf(buf, PAGE_SIZE, "%llu\n", ctime);
594 }
595
596 static ssize_t
597 nilfs_segctor_last_nongc_write_time_show(struct nilfs_segctor_attr *attr,
598                                          struct the_nilfs *nilfs,
599                                          char *buf)
600 {
601         time64_t nongc_ctime;
602
603         down_read(&nilfs->ns_segctor_sem);
604         nongc_ctime = nilfs->ns_nongc_ctime;
605         up_read(&nilfs->ns_segctor_sem);
606
607         return NILFS_SHOW_TIME(nongc_ctime, buf);
608 }
609
610 static ssize_t
611 nilfs_segctor_last_nongc_write_time_secs_show(struct nilfs_segctor_attr *attr,
612                                                 struct the_nilfs *nilfs,
613                                                 char *buf)
614 {
615         time64_t nongc_ctime;
616
617         down_read(&nilfs->ns_segctor_sem);
618         nongc_ctime = nilfs->ns_nongc_ctime;
619         up_read(&nilfs->ns_segctor_sem);
620
621         return snprintf(buf, PAGE_SIZE, "%llu\n", nongc_ctime);
622 }
623
624 static ssize_t
625 nilfs_segctor_dirty_data_blocks_count_show(struct nilfs_segctor_attr *attr,
626                                             struct the_nilfs *nilfs,
627                                             char *buf)
628 {
629         u32 ndirtyblks;
630
631         down_read(&nilfs->ns_segctor_sem);
632         ndirtyblks = atomic_read(&nilfs->ns_ndirtyblks);
633         up_read(&nilfs->ns_segctor_sem);
634
635         return snprintf(buf, PAGE_SIZE, "%u\n", ndirtyblks);
636 }
637
638 static const char segctor_readme_str[] =
639         "The segctor group contains attributes that describe\n"
640         "segctor thread activity details.\n\n"
641         "(1) last_pseg_block\n"
642         "\tshow start block number of the latest segment.\n\n"
643         "(2) last_seg_sequence\n"
644         "\tshow sequence value of the latest segment.\n\n"
645         "(3) last_seg_checkpoint\n"
646         "\tshow checkpoint number of the latest segment.\n\n"
647         "(4) current_seg_sequence\n\tshow segment sequence counter.\n\n"
648         "(5) current_last_full_seg\n"
649         "\tshow index number of the latest full segment.\n\n"
650         "(6) next_full_seg\n"
651         "\tshow index number of the full segment index to be used next.\n\n"
652         "(7) next_pseg_offset\n"
653         "\tshow offset of next partial segment in the current full segment.\n\n"
654         "(8) next_checkpoint\n\tshow next checkpoint number.\n\n"
655         "(9) last_seg_write_time\n"
656         "\tshow write time of the last segment in human-readable format.\n\n"
657         "(10) last_seg_write_time_secs\n"
658         "\tshow write time of the last segment in seconds.\n\n"
659         "(11) last_nongc_write_time\n"
660         "\tshow write time of the last segment not for cleaner operation "
661         "in human-readable format.\n\n"
662         "(12) last_nongc_write_time_secs\n"
663         "\tshow write time of the last segment not for cleaner operation "
664         "in seconds.\n\n"
665         "(13) dirty_data_blocks_count\n"
666         "\tshow number of dirty data blocks.\n\n";
667
668 static ssize_t
669 nilfs_segctor_README_show(struct nilfs_segctor_attr *attr,
670                           struct the_nilfs *nilfs, char *buf)
671 {
672         return snprintf(buf, PAGE_SIZE, segctor_readme_str);
673 }
674
675 NILFS_SEGCTOR_RO_ATTR(last_pseg_block);
676 NILFS_SEGCTOR_RO_ATTR(last_seg_sequence);
677 NILFS_SEGCTOR_RO_ATTR(last_seg_checkpoint);
678 NILFS_SEGCTOR_RO_ATTR(current_seg_sequence);
679 NILFS_SEGCTOR_RO_ATTR(current_last_full_seg);
680 NILFS_SEGCTOR_RO_ATTR(next_full_seg);
681 NILFS_SEGCTOR_RO_ATTR(next_pseg_offset);
682 NILFS_SEGCTOR_RO_ATTR(next_checkpoint);
683 NILFS_SEGCTOR_RO_ATTR(last_seg_write_time);
684 NILFS_SEGCTOR_RO_ATTR(last_seg_write_time_secs);
685 NILFS_SEGCTOR_RO_ATTR(last_nongc_write_time);
686 NILFS_SEGCTOR_RO_ATTR(last_nongc_write_time_secs);
687 NILFS_SEGCTOR_RO_ATTR(dirty_data_blocks_count);
688 NILFS_SEGCTOR_RO_ATTR(README);
689
690 static struct attribute *nilfs_segctor_attrs[] = {
691         NILFS_SEGCTOR_ATTR_LIST(last_pseg_block),
692         NILFS_SEGCTOR_ATTR_LIST(last_seg_sequence),
693         NILFS_SEGCTOR_ATTR_LIST(last_seg_checkpoint),
694         NILFS_SEGCTOR_ATTR_LIST(current_seg_sequence),
695         NILFS_SEGCTOR_ATTR_LIST(current_last_full_seg),
696         NILFS_SEGCTOR_ATTR_LIST(next_full_seg),
697         NILFS_SEGCTOR_ATTR_LIST(next_pseg_offset),
698         NILFS_SEGCTOR_ATTR_LIST(next_checkpoint),
699         NILFS_SEGCTOR_ATTR_LIST(last_seg_write_time),
700         NILFS_SEGCTOR_ATTR_LIST(last_seg_write_time_secs),
701         NILFS_SEGCTOR_ATTR_LIST(last_nongc_write_time),
702         NILFS_SEGCTOR_ATTR_LIST(last_nongc_write_time_secs),
703         NILFS_SEGCTOR_ATTR_LIST(dirty_data_blocks_count),
704         NILFS_SEGCTOR_ATTR_LIST(README),
705         NULL,
706 };
707
708 NILFS_DEV_INT_GROUP_OPS(segctor, dev);
709 NILFS_DEV_INT_GROUP_TYPE(segctor, dev);
710 NILFS_DEV_INT_GROUP_FNS(segctor, dev);
711
712 /************************************************************************
713  *                        NILFS superblock attrs                        *
714  ************************************************************************/
715
716 static ssize_t
717 nilfs_superblock_sb_write_time_show(struct nilfs_superblock_attr *attr,
718                                      struct the_nilfs *nilfs,
719                                      char *buf)
720 {
721         time64_t sbwtime;
722
723         down_read(&nilfs->ns_sem);
724         sbwtime = nilfs->ns_sbwtime;
725         up_read(&nilfs->ns_sem);
726
727         return NILFS_SHOW_TIME(sbwtime, buf);
728 }
729
730 static ssize_t
731 nilfs_superblock_sb_write_time_secs_show(struct nilfs_superblock_attr *attr,
732                                          struct the_nilfs *nilfs,
733                                          char *buf)
734 {
735         time64_t sbwtime;
736
737         down_read(&nilfs->ns_sem);
738         sbwtime = nilfs->ns_sbwtime;
739         up_read(&nilfs->ns_sem);
740
741         return snprintf(buf, PAGE_SIZE, "%llu\n", sbwtime);
742 }
743
744 static ssize_t
745 nilfs_superblock_sb_write_count_show(struct nilfs_superblock_attr *attr,
746                                       struct the_nilfs *nilfs,
747                                       char *buf)
748 {
749         unsigned int sbwcount;
750
751         down_read(&nilfs->ns_sem);
752         sbwcount = nilfs->ns_sbwcount;
753         up_read(&nilfs->ns_sem);
754
755         return snprintf(buf, PAGE_SIZE, "%u\n", sbwcount);
756 }
757
758 static ssize_t
759 nilfs_superblock_sb_update_frequency_show(struct nilfs_superblock_attr *attr,
760                                             struct the_nilfs *nilfs,
761                                             char *buf)
762 {
763         unsigned int sb_update_freq;
764
765         down_read(&nilfs->ns_sem);
766         sb_update_freq = nilfs->ns_sb_update_freq;
767         up_read(&nilfs->ns_sem);
768
769         return snprintf(buf, PAGE_SIZE, "%u\n", sb_update_freq);
770 }
771
772 static ssize_t
773 nilfs_superblock_sb_update_frequency_store(struct nilfs_superblock_attr *attr,
774                                             struct the_nilfs *nilfs,
775                                             const char *buf, size_t count)
776 {
777         unsigned int val;
778         int err;
779
780         err = kstrtouint(skip_spaces(buf), 0, &val);
781         if (err) {
782                 nilfs_err(nilfs->ns_sb, "unable to convert string: err=%d",
783                           err);
784                 return err;
785         }
786
787         if (val < NILFS_SB_FREQ) {
788                 val = NILFS_SB_FREQ;
789                 nilfs_warn(nilfs->ns_sb,
790                            "superblock update frequency cannot be lesser than 10 seconds");
791         }
792
793         down_write(&nilfs->ns_sem);
794         nilfs->ns_sb_update_freq = val;
795         up_write(&nilfs->ns_sem);
796
797         return count;
798 }
799
800 static const char sb_readme_str[] =
801         "The superblock group contains attributes that describe\n"
802         "superblock's details.\n\n"
803         "(1) sb_write_time\n\tshow previous write time of super block "
804         "in human-readable format.\n\n"
805         "(2) sb_write_time_secs\n\tshow previous write time of super block "
806         "in seconds.\n\n"
807         "(3) sb_write_count\n\tshow write count of super block.\n\n"
808         "(4) sb_update_frequency\n"
809         "\tshow/set interval of periodical update of superblock (in seconds).\n\n"
810         "\tYou can set preferable frequency of superblock update by command:\n\n"
811         "\t'echo <val> > /sys/fs/<nilfs>/<dev>/superblock/sb_update_frequency'\n";
812
813 static ssize_t
814 nilfs_superblock_README_show(struct nilfs_superblock_attr *attr,
815                                 struct the_nilfs *nilfs, char *buf)
816 {
817         return snprintf(buf, PAGE_SIZE, sb_readme_str);
818 }
819
820 NILFS_SUPERBLOCK_RO_ATTR(sb_write_time);
821 NILFS_SUPERBLOCK_RO_ATTR(sb_write_time_secs);
822 NILFS_SUPERBLOCK_RO_ATTR(sb_write_count);
823 NILFS_SUPERBLOCK_RW_ATTR(sb_update_frequency);
824 NILFS_SUPERBLOCK_RO_ATTR(README);
825
826 static struct attribute *nilfs_superblock_attrs[] = {
827         NILFS_SUPERBLOCK_ATTR_LIST(sb_write_time),
828         NILFS_SUPERBLOCK_ATTR_LIST(sb_write_time_secs),
829         NILFS_SUPERBLOCK_ATTR_LIST(sb_write_count),
830         NILFS_SUPERBLOCK_ATTR_LIST(sb_update_frequency),
831         NILFS_SUPERBLOCK_ATTR_LIST(README),
832         NULL,
833 };
834
835 NILFS_DEV_INT_GROUP_OPS(superblock, dev);
836 NILFS_DEV_INT_GROUP_TYPE(superblock, dev);
837 NILFS_DEV_INT_GROUP_FNS(superblock, dev);
838
839 /************************************************************************
840  *                        NILFS device attrs                            *
841  ************************************************************************/
842
843 static
844 ssize_t nilfs_dev_revision_show(struct nilfs_dev_attr *attr,
845                                 struct the_nilfs *nilfs,
846                                 char *buf)
847 {
848         struct nilfs_super_block **sbp = nilfs->ns_sbp;
849         u32 major = le32_to_cpu(sbp[0]->s_rev_level);
850         u16 minor = le16_to_cpu(sbp[0]->s_minor_rev_level);
851
852         return snprintf(buf, PAGE_SIZE, "%d.%d\n", major, minor);
853 }
854
855 static
856 ssize_t nilfs_dev_blocksize_show(struct nilfs_dev_attr *attr,
857                                  struct the_nilfs *nilfs,
858                                  char *buf)
859 {
860         return snprintf(buf, PAGE_SIZE, "%u\n", nilfs->ns_blocksize);
861 }
862
863 static
864 ssize_t nilfs_dev_device_size_show(struct nilfs_dev_attr *attr,
865                                     struct the_nilfs *nilfs,
866                                     char *buf)
867 {
868         struct nilfs_super_block **sbp = nilfs->ns_sbp;
869         u64 dev_size = le64_to_cpu(sbp[0]->s_dev_size);
870
871         return snprintf(buf, PAGE_SIZE, "%llu\n", dev_size);
872 }
873
874 static
875 ssize_t nilfs_dev_free_blocks_show(struct nilfs_dev_attr *attr,
876                                    struct the_nilfs *nilfs,
877                                    char *buf)
878 {
879         sector_t free_blocks = 0;
880
881         nilfs_count_free_blocks(nilfs, &free_blocks);
882         return snprintf(buf, PAGE_SIZE, "%llu\n",
883                         (unsigned long long)free_blocks);
884 }
885
886 static
887 ssize_t nilfs_dev_uuid_show(struct nilfs_dev_attr *attr,
888                             struct the_nilfs *nilfs,
889                             char *buf)
890 {
891         struct nilfs_super_block **sbp = nilfs->ns_sbp;
892
893         return snprintf(buf, PAGE_SIZE, "%pUb\n", sbp[0]->s_uuid);
894 }
895
896 static
897 ssize_t nilfs_dev_volume_name_show(struct nilfs_dev_attr *attr,
898                                     struct the_nilfs *nilfs,
899                                     char *buf)
900 {
901         struct nilfs_super_block **sbp = nilfs->ns_sbp;
902
903         return scnprintf(buf, sizeof(sbp[0]->s_volume_name), "%s\n",
904                          sbp[0]->s_volume_name);
905 }
906
907 static const char dev_readme_str[] =
908         "The <device> group contains attributes that describe file system\n"
909         "partition's details.\n\n"
910         "(1) revision\n\tshow NILFS file system revision.\n\n"
911         "(2) blocksize\n\tshow volume block size in bytes.\n\n"
912         "(3) device_size\n\tshow volume size in bytes.\n\n"
913         "(4) free_blocks\n\tshow count of free blocks on volume.\n\n"
914         "(5) uuid\n\tshow volume's UUID.\n\n"
915         "(6) volume_name\n\tshow volume's name.\n\n";
916
917 static ssize_t nilfs_dev_README_show(struct nilfs_dev_attr *attr,
918                                      struct the_nilfs *nilfs,
919                                      char *buf)
920 {
921         return snprintf(buf, PAGE_SIZE, dev_readme_str);
922 }
923
924 NILFS_DEV_RO_ATTR(revision);
925 NILFS_DEV_RO_ATTR(blocksize);
926 NILFS_DEV_RO_ATTR(device_size);
927 NILFS_DEV_RO_ATTR(free_blocks);
928 NILFS_DEV_RO_ATTR(uuid);
929 NILFS_DEV_RO_ATTR(volume_name);
930 NILFS_DEV_RO_ATTR(README);
931
932 static struct attribute *nilfs_dev_attrs[] = {
933         NILFS_DEV_ATTR_LIST(revision),
934         NILFS_DEV_ATTR_LIST(blocksize),
935         NILFS_DEV_ATTR_LIST(device_size),
936         NILFS_DEV_ATTR_LIST(free_blocks),
937         NILFS_DEV_ATTR_LIST(uuid),
938         NILFS_DEV_ATTR_LIST(volume_name),
939         NILFS_DEV_ATTR_LIST(README),
940         NULL,
941 };
942
943 static ssize_t nilfs_dev_attr_show(struct kobject *kobj,
944                                     struct attribute *attr, char *buf)
945 {
946         struct the_nilfs *nilfs = container_of(kobj, struct the_nilfs,
947                                                 ns_dev_kobj);
948         struct nilfs_dev_attr *a = container_of(attr, struct nilfs_dev_attr,
949                                                 attr);
950
951         return a->show ? a->show(a, nilfs, buf) : 0;
952 }
953
954 static ssize_t nilfs_dev_attr_store(struct kobject *kobj,
955                                     struct attribute *attr,
956                                     const char *buf, size_t len)
957 {
958         struct the_nilfs *nilfs = container_of(kobj, struct the_nilfs,
959                                                 ns_dev_kobj);
960         struct nilfs_dev_attr *a = container_of(attr, struct nilfs_dev_attr,
961                                                 attr);
962
963         return a->store ? a->store(a, nilfs, buf, len) : 0;
964 }
965
966 static void nilfs_dev_attr_release(struct kobject *kobj)
967 {
968         struct the_nilfs *nilfs = container_of(kobj, struct the_nilfs,
969                                                 ns_dev_kobj);
970         complete(&nilfs->ns_dev_kobj_unregister);
971 }
972
973 static const struct sysfs_ops nilfs_dev_attr_ops = {
974         .show   = nilfs_dev_attr_show,
975         .store  = nilfs_dev_attr_store,
976 };
977
978 static struct kobj_type nilfs_dev_ktype = {
979         .default_attrs  = nilfs_dev_attrs,
980         .sysfs_ops      = &nilfs_dev_attr_ops,
981         .release        = nilfs_dev_attr_release,
982 };
983
984 int nilfs_sysfs_create_device_group(struct super_block *sb)
985 {
986         struct the_nilfs *nilfs = sb->s_fs_info;
987         size_t devgrp_size = sizeof(struct nilfs_sysfs_dev_subgroups);
988         int err;
989
990         nilfs->ns_dev_subgroups = kzalloc(devgrp_size, GFP_KERNEL);
991         if (unlikely(!nilfs->ns_dev_subgroups)) {
992                 err = -ENOMEM;
993                 nilfs_err(sb, "unable to allocate memory for device group");
994                 goto failed_create_device_group;
995         }
996
997         nilfs->ns_dev_kobj.kset = nilfs_kset;
998         init_completion(&nilfs->ns_dev_kobj_unregister);
999         err = kobject_init_and_add(&nilfs->ns_dev_kobj, &nilfs_dev_ktype, NULL,
1000                                     "%s", sb->s_id);
1001         if (err)
1002                 goto free_dev_subgroups;
1003
1004         err = nilfs_sysfs_create_mounted_snapshots_group(nilfs);
1005         if (err)
1006                 goto cleanup_dev_kobject;
1007
1008         err = nilfs_sysfs_create_checkpoints_group(nilfs);
1009         if (err)
1010                 goto delete_mounted_snapshots_group;
1011
1012         err = nilfs_sysfs_create_segments_group(nilfs);
1013         if (err)
1014                 goto delete_checkpoints_group;
1015
1016         err = nilfs_sysfs_create_superblock_group(nilfs);
1017         if (err)
1018                 goto delete_segments_group;
1019
1020         err = nilfs_sysfs_create_segctor_group(nilfs);
1021         if (err)
1022                 goto delete_superblock_group;
1023
1024         return 0;
1025
1026 delete_superblock_group:
1027         nilfs_sysfs_delete_superblock_group(nilfs);
1028
1029 delete_segments_group:
1030         nilfs_sysfs_delete_segments_group(nilfs);
1031
1032 delete_checkpoints_group:
1033         nilfs_sysfs_delete_checkpoints_group(nilfs);
1034
1035 delete_mounted_snapshots_group:
1036         nilfs_sysfs_delete_mounted_snapshots_group(nilfs);
1037
1038 cleanup_dev_kobject:
1039         kobject_del(&nilfs->ns_dev_kobj);
1040
1041 free_dev_subgroups:
1042         kfree(nilfs->ns_dev_subgroups);
1043
1044 failed_create_device_group:
1045         return err;
1046 }
1047
1048 void nilfs_sysfs_delete_device_group(struct the_nilfs *nilfs)
1049 {
1050         nilfs_sysfs_delete_mounted_snapshots_group(nilfs);
1051         nilfs_sysfs_delete_checkpoints_group(nilfs);
1052         nilfs_sysfs_delete_segments_group(nilfs);
1053         nilfs_sysfs_delete_superblock_group(nilfs);
1054         nilfs_sysfs_delete_segctor_group(nilfs);
1055         kobject_del(&nilfs->ns_dev_kobj);
1056         kfree(nilfs->ns_dev_subgroups);
1057 }
1058
1059 /************************************************************************
1060  *                        NILFS feature attrs                           *
1061  ************************************************************************/
1062
1063 static ssize_t nilfs_feature_revision_show(struct kobject *kobj,
1064                                             struct attribute *attr, char *buf)
1065 {
1066         return snprintf(buf, PAGE_SIZE, "%d.%d\n",
1067                         NILFS_CURRENT_REV, NILFS_MINOR_REV);
1068 }
1069
1070 static const char features_readme_str[] =
1071         "The features group contains attributes that describe NILFS file\n"
1072         "system driver features.\n\n"
1073         "(1) revision\n\tshow current revision of NILFS file system driver.\n";
1074
1075 static ssize_t nilfs_feature_README_show(struct kobject *kobj,
1076                                          struct attribute *attr,
1077                                          char *buf)
1078 {
1079         return snprintf(buf, PAGE_SIZE, features_readme_str);
1080 }
1081
1082 NILFS_FEATURE_RO_ATTR(revision);
1083 NILFS_FEATURE_RO_ATTR(README);
1084
1085 static struct attribute *nilfs_feature_attrs[] = {
1086         NILFS_FEATURE_ATTR_LIST(revision),
1087         NILFS_FEATURE_ATTR_LIST(README),
1088         NULL,
1089 };
1090
1091 static const struct attribute_group nilfs_feature_attr_group = {
1092         .name = "features",
1093         .attrs = nilfs_feature_attrs,
1094 };
1095
1096 int __init nilfs_sysfs_init(void)
1097 {
1098         int err;
1099
1100         nilfs_kset = kset_create_and_add(NILFS_ROOT_GROUP_NAME, NULL, fs_kobj);
1101         if (!nilfs_kset) {
1102                 err = -ENOMEM;
1103                 nilfs_err(NULL, "unable to create sysfs entry: err=%d", err);
1104                 goto failed_sysfs_init;
1105         }
1106
1107         err = sysfs_create_group(&nilfs_kset->kobj, &nilfs_feature_attr_group);
1108         if (unlikely(err)) {
1109                 nilfs_err(NULL, "unable to create feature group: err=%d", err);
1110                 goto cleanup_sysfs_init;
1111         }
1112
1113         return 0;
1114
1115 cleanup_sysfs_init:
1116         kset_unregister(nilfs_kset);
1117
1118 failed_sysfs_init:
1119         return err;
1120 }
1121
1122 void nilfs_sysfs_exit(void)
1123 {
1124         sysfs_remove_group(&nilfs_kset->kobj, &nilfs_feature_attr_group);
1125         kset_unregister(nilfs_kset);
1126 }