xref: /openbmc/linux/fs/nilfs2/sysfs.c (revision 7a010c3c)
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_DEV_INT_GROUP_OPS(name, parent_name) \
23 static ssize_t nilfs_##name##_attr_show(struct kobject *kobj, \
24 					struct attribute *attr, char *buf) \
25 { \
26 	struct the_nilfs *nilfs = container_of(kobj->parent, \
27 						struct the_nilfs, \
28 						ns_##parent_name##_kobj); \
29 	struct nilfs_##name##_attr *a = container_of(attr, \
30 						struct nilfs_##name##_attr, \
31 						attr); \
32 	return a->show ? a->show(a, nilfs, buf) : 0; \
33 } \
34 static ssize_t nilfs_##name##_attr_store(struct kobject *kobj, \
35 					 struct attribute *attr, \
36 					 const char *buf, size_t len) \
37 { \
38 	struct the_nilfs *nilfs = container_of(kobj->parent, \
39 						struct the_nilfs, \
40 						ns_##parent_name##_kobj); \
41 	struct nilfs_##name##_attr *a = container_of(attr, \
42 						struct nilfs_##name##_attr, \
43 						attr); \
44 	return a->store ? a->store(a, nilfs, buf, len) : 0; \
45 } \
46 static const struct sysfs_ops nilfs_##name##_attr_ops = { \
47 	.show	= nilfs_##name##_attr_show, \
48 	.store	= nilfs_##name##_attr_store, \
49 }
50 
51 #define NILFS_DEV_INT_GROUP_TYPE(name, parent_name) \
52 static void nilfs_##name##_attr_release(struct kobject *kobj) \
53 { \
54 	struct nilfs_sysfs_##parent_name##_subgroups *subgroups = container_of(kobj, \
55 						struct nilfs_sysfs_##parent_name##_subgroups, \
56 						sg_##name##_kobj); \
57 	complete(&subgroups->sg_##name##_kobj_unregister); \
58 } \
59 static struct kobj_type nilfs_##name##_ktype = { \
60 	.default_attrs	= nilfs_##name##_attrs, \
61 	.sysfs_ops	= &nilfs_##name##_attr_ops, \
62 	.release	= nilfs_##name##_attr_release, \
63 }
64 
65 #define NILFS_DEV_INT_GROUP_FNS(name, parent_name) \
66 static int nilfs_sysfs_create_##name##_group(struct the_nilfs *nilfs) \
67 { \
68 	struct kobject *parent; \
69 	struct kobject *kobj; \
70 	struct completion *kobj_unregister; \
71 	struct nilfs_sysfs_##parent_name##_subgroups *subgroups; \
72 	int err; \
73 	subgroups = nilfs->ns_##parent_name##_subgroups; \
74 	kobj = &subgroups->sg_##name##_kobj; \
75 	kobj_unregister = &subgroups->sg_##name##_kobj_unregister; \
76 	parent = &nilfs->ns_##parent_name##_kobj; \
77 	kobj->kset = nilfs_kset; \
78 	init_completion(kobj_unregister); \
79 	err = kobject_init_and_add(kobj, &nilfs_##name##_ktype, parent, \
80 				    #name); \
81 	if (err) \
82 		kobject_put(kobj); \
83 	return err; \
84 } \
85 static void nilfs_sysfs_delete_##name##_group(struct the_nilfs *nilfs) \
86 { \
87 	kobject_put(&nilfs->ns_##parent_name##_subgroups->sg_##name##_kobj); \
88 }
89 
90 /************************************************************************
91  *                        NILFS snapshot attrs                          *
92  ************************************************************************/
93 
94 static ssize_t
95 nilfs_snapshot_inodes_count_show(struct nilfs_snapshot_attr *attr,
96 				 struct nilfs_root *root, char *buf)
97 {
98 	return snprintf(buf, PAGE_SIZE, "%llu\n",
99 			(unsigned long long)atomic64_read(&root->inodes_count));
100 }
101 
102 static ssize_t
103 nilfs_snapshot_blocks_count_show(struct nilfs_snapshot_attr *attr,
104 				 struct nilfs_root *root, char *buf)
105 {
106 	return snprintf(buf, PAGE_SIZE, "%llu\n",
107 			(unsigned long long)atomic64_read(&root->blocks_count));
108 }
109 
110 static const char snapshot_readme_str[] =
111 	"The group contains details about mounted snapshot.\n\n"
112 	"(1) inodes_count\n\tshow number of inodes for snapshot.\n\n"
113 	"(2) blocks_count\n\tshow number of blocks for snapshot.\n\n";
114 
115 static ssize_t
116 nilfs_snapshot_README_show(struct nilfs_snapshot_attr *attr,
117 			    struct nilfs_root *root, char *buf)
118 {
119 	return snprintf(buf, PAGE_SIZE, snapshot_readme_str);
120 }
121 
122 NILFS_SNAPSHOT_RO_ATTR(inodes_count);
123 NILFS_SNAPSHOT_RO_ATTR(blocks_count);
124 NILFS_SNAPSHOT_RO_ATTR(README);
125 
126 static struct attribute *nilfs_snapshot_attrs[] = {
127 	NILFS_SNAPSHOT_ATTR_LIST(inodes_count),
128 	NILFS_SNAPSHOT_ATTR_LIST(blocks_count),
129 	NILFS_SNAPSHOT_ATTR_LIST(README),
130 	NULL,
131 };
132 
133 static ssize_t nilfs_snapshot_attr_show(struct kobject *kobj,
134 					struct attribute *attr, char *buf)
135 {
136 	struct nilfs_root *root =
137 			container_of(kobj, struct nilfs_root, snapshot_kobj);
138 	struct nilfs_snapshot_attr *a =
139 			container_of(attr, struct nilfs_snapshot_attr, attr);
140 
141 	return a->show ? a->show(a, root, buf) : 0;
142 }
143 
144 static ssize_t nilfs_snapshot_attr_store(struct kobject *kobj,
145 					 struct attribute *attr,
146 					 const char *buf, size_t len)
147 {
148 	struct nilfs_root *root =
149 			container_of(kobj, struct nilfs_root, snapshot_kobj);
150 	struct nilfs_snapshot_attr *a =
151 			container_of(attr, struct nilfs_snapshot_attr, attr);
152 
153 	return a->store ? a->store(a, root, buf, len) : 0;
154 }
155 
156 static void nilfs_snapshot_attr_release(struct kobject *kobj)
157 {
158 	struct nilfs_root *root = container_of(kobj, struct nilfs_root,
159 						snapshot_kobj);
160 	complete(&root->snapshot_kobj_unregister);
161 }
162 
163 static const struct sysfs_ops nilfs_snapshot_attr_ops = {
164 	.show	= nilfs_snapshot_attr_show,
165 	.store	= nilfs_snapshot_attr_store,
166 };
167 
168 static struct kobj_type nilfs_snapshot_ktype = {
169 	.default_attrs	= nilfs_snapshot_attrs,
170 	.sysfs_ops	= &nilfs_snapshot_attr_ops,
171 	.release	= nilfs_snapshot_attr_release,
172 };
173 
174 int nilfs_sysfs_create_snapshot_group(struct nilfs_root *root)
175 {
176 	struct the_nilfs *nilfs;
177 	struct kobject *parent;
178 	int err;
179 
180 	nilfs = root->nilfs;
181 	parent = &nilfs->ns_dev_subgroups->sg_mounted_snapshots_kobj;
182 	root->snapshot_kobj.kset = nilfs_kset;
183 	init_completion(&root->snapshot_kobj_unregister);
184 
185 	if (root->cno == NILFS_CPTREE_CURRENT_CNO) {
186 		err = kobject_init_and_add(&root->snapshot_kobj,
187 					    &nilfs_snapshot_ktype,
188 					    &nilfs->ns_dev_kobj,
189 					    "current_checkpoint");
190 	} else {
191 		err = kobject_init_and_add(&root->snapshot_kobj,
192 					    &nilfs_snapshot_ktype,
193 					    parent,
194 					    "%llu", root->cno);
195 	}
196 
197 	if (err)
198 		kobject_put(&root->snapshot_kobj);
199 
200 	return err;
201 }
202 
203 void nilfs_sysfs_delete_snapshot_group(struct nilfs_root *root)
204 {
205 	kobject_put(&root->snapshot_kobj);
206 }
207 
208 /************************************************************************
209  *                    NILFS mounted snapshots attrs                     *
210  ************************************************************************/
211 
212 static const char mounted_snapshots_readme_str[] =
213 	"The mounted_snapshots group contains group for\n"
214 	"every mounted snapshot.\n";
215 
216 static ssize_t
217 nilfs_mounted_snapshots_README_show(struct nilfs_mounted_snapshots_attr *attr,
218 				    struct the_nilfs *nilfs, char *buf)
219 {
220 	return snprintf(buf, PAGE_SIZE, mounted_snapshots_readme_str);
221 }
222 
223 NILFS_MOUNTED_SNAPSHOTS_RO_ATTR(README);
224 
225 static struct attribute *nilfs_mounted_snapshots_attrs[] = {
226 	NILFS_MOUNTED_SNAPSHOTS_ATTR_LIST(README),
227 	NULL,
228 };
229 
230 NILFS_DEV_INT_GROUP_OPS(mounted_snapshots, dev);
231 NILFS_DEV_INT_GROUP_TYPE(mounted_snapshots, dev);
232 NILFS_DEV_INT_GROUP_FNS(mounted_snapshots, dev);
233 
234 /************************************************************************
235  *                      NILFS checkpoints attrs                         *
236  ************************************************************************/
237 
238 static ssize_t
239 nilfs_checkpoints_checkpoints_number_show(struct nilfs_checkpoints_attr *attr,
240 					    struct the_nilfs *nilfs,
241 					    char *buf)
242 {
243 	__u64 ncheckpoints;
244 	struct nilfs_cpstat cpstat;
245 	int err;
246 
247 	down_read(&nilfs->ns_segctor_sem);
248 	err = nilfs_cpfile_get_stat(nilfs->ns_cpfile, &cpstat);
249 	up_read(&nilfs->ns_segctor_sem);
250 	if (err < 0) {
251 		nilfs_err(nilfs->ns_sb, "unable to get checkpoint stat: err=%d",
252 			  err);
253 		return err;
254 	}
255 
256 	ncheckpoints = cpstat.cs_ncps;
257 
258 	return snprintf(buf, PAGE_SIZE, "%llu\n", ncheckpoints);
259 }
260 
261 static ssize_t
262 nilfs_checkpoints_snapshots_number_show(struct nilfs_checkpoints_attr *attr,
263 					struct the_nilfs *nilfs,
264 					char *buf)
265 {
266 	__u64 nsnapshots;
267 	struct nilfs_cpstat cpstat;
268 	int err;
269 
270 	down_read(&nilfs->ns_segctor_sem);
271 	err = nilfs_cpfile_get_stat(nilfs->ns_cpfile, &cpstat);
272 	up_read(&nilfs->ns_segctor_sem);
273 	if (err < 0) {
274 		nilfs_err(nilfs->ns_sb, "unable to get checkpoint stat: err=%d",
275 			  err);
276 		return err;
277 	}
278 
279 	nsnapshots = cpstat.cs_nsss;
280 
281 	return snprintf(buf, PAGE_SIZE, "%llu\n", nsnapshots);
282 }
283 
284 static ssize_t
285 nilfs_checkpoints_last_seg_checkpoint_show(struct nilfs_checkpoints_attr *attr,
286 					    struct the_nilfs *nilfs,
287 					    char *buf)
288 {
289 	__u64 last_cno;
290 
291 	spin_lock(&nilfs->ns_last_segment_lock);
292 	last_cno = nilfs->ns_last_cno;
293 	spin_unlock(&nilfs->ns_last_segment_lock);
294 
295 	return snprintf(buf, PAGE_SIZE, "%llu\n", last_cno);
296 }
297 
298 static ssize_t
299 nilfs_checkpoints_next_checkpoint_show(struct nilfs_checkpoints_attr *attr,
300 					struct the_nilfs *nilfs,
301 					char *buf)
302 {
303 	__u64 cno;
304 
305 	down_read(&nilfs->ns_segctor_sem);
306 	cno = nilfs->ns_cno;
307 	up_read(&nilfs->ns_segctor_sem);
308 
309 	return snprintf(buf, PAGE_SIZE, "%llu\n", cno);
310 }
311 
312 static const char checkpoints_readme_str[] =
313 	"The checkpoints group contains attributes that describe\n"
314 	"details about volume's checkpoints.\n\n"
315 	"(1) checkpoints_number\n\tshow number of checkpoints on volume.\n\n"
316 	"(2) snapshots_number\n\tshow number of snapshots on volume.\n\n"
317 	"(3) last_seg_checkpoint\n"
318 	"\tshow checkpoint number of the latest segment.\n\n"
319 	"(4) next_checkpoint\n\tshow next checkpoint number.\n\n";
320 
321 static ssize_t
322 nilfs_checkpoints_README_show(struct nilfs_checkpoints_attr *attr,
323 				struct the_nilfs *nilfs, char *buf)
324 {
325 	return snprintf(buf, PAGE_SIZE, checkpoints_readme_str);
326 }
327 
328 NILFS_CHECKPOINTS_RO_ATTR(checkpoints_number);
329 NILFS_CHECKPOINTS_RO_ATTR(snapshots_number);
330 NILFS_CHECKPOINTS_RO_ATTR(last_seg_checkpoint);
331 NILFS_CHECKPOINTS_RO_ATTR(next_checkpoint);
332 NILFS_CHECKPOINTS_RO_ATTR(README);
333 
334 static struct attribute *nilfs_checkpoints_attrs[] = {
335 	NILFS_CHECKPOINTS_ATTR_LIST(checkpoints_number),
336 	NILFS_CHECKPOINTS_ATTR_LIST(snapshots_number),
337 	NILFS_CHECKPOINTS_ATTR_LIST(last_seg_checkpoint),
338 	NILFS_CHECKPOINTS_ATTR_LIST(next_checkpoint),
339 	NILFS_CHECKPOINTS_ATTR_LIST(README),
340 	NULL,
341 };
342 
343 NILFS_DEV_INT_GROUP_OPS(checkpoints, dev);
344 NILFS_DEV_INT_GROUP_TYPE(checkpoints, dev);
345 NILFS_DEV_INT_GROUP_FNS(checkpoints, dev);
346 
347 /************************************************************************
348  *                        NILFS segments attrs                          *
349  ************************************************************************/
350 
351 static ssize_t
352 nilfs_segments_segments_number_show(struct nilfs_segments_attr *attr,
353 				     struct the_nilfs *nilfs,
354 				     char *buf)
355 {
356 	return snprintf(buf, PAGE_SIZE, "%lu\n", nilfs->ns_nsegments);
357 }
358 
359 static ssize_t
360 nilfs_segments_blocks_per_segment_show(struct nilfs_segments_attr *attr,
361 					struct the_nilfs *nilfs,
362 					char *buf)
363 {
364 	return snprintf(buf, PAGE_SIZE, "%lu\n", nilfs->ns_blocks_per_segment);
365 }
366 
367 static ssize_t
368 nilfs_segments_clean_segments_show(struct nilfs_segments_attr *attr,
369 				    struct the_nilfs *nilfs,
370 				    char *buf)
371 {
372 	unsigned long ncleansegs;
373 
374 	down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
375 	ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile);
376 	up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
377 
378 	return snprintf(buf, PAGE_SIZE, "%lu\n", ncleansegs);
379 }
380 
381 static ssize_t
382 nilfs_segments_dirty_segments_show(struct nilfs_segments_attr *attr,
383 				    struct the_nilfs *nilfs,
384 				    char *buf)
385 {
386 	struct nilfs_sustat sustat;
387 	int err;
388 
389 	down_read(&nilfs->ns_segctor_sem);
390 	err = nilfs_sufile_get_stat(nilfs->ns_sufile, &sustat);
391 	up_read(&nilfs->ns_segctor_sem);
392 	if (err < 0) {
393 		nilfs_err(nilfs->ns_sb, "unable to get segment stat: err=%d",
394 			  err);
395 		return err;
396 	}
397 
398 	return snprintf(buf, PAGE_SIZE, "%llu\n", sustat.ss_ndirtysegs);
399 }
400 
401 static const char segments_readme_str[] =
402 	"The segments group contains attributes that describe\n"
403 	"details about volume's segments.\n\n"
404 	"(1) segments_number\n\tshow number of segments on volume.\n\n"
405 	"(2) blocks_per_segment\n\tshow number of blocks in segment.\n\n"
406 	"(3) clean_segments\n\tshow count of clean segments.\n\n"
407 	"(4) dirty_segments\n\tshow count of dirty segments.\n\n";
408 
409 static ssize_t
410 nilfs_segments_README_show(struct nilfs_segments_attr *attr,
411 			    struct the_nilfs *nilfs,
412 			    char *buf)
413 {
414 	return snprintf(buf, PAGE_SIZE, segments_readme_str);
415 }
416 
417 NILFS_SEGMENTS_RO_ATTR(segments_number);
418 NILFS_SEGMENTS_RO_ATTR(blocks_per_segment);
419 NILFS_SEGMENTS_RO_ATTR(clean_segments);
420 NILFS_SEGMENTS_RO_ATTR(dirty_segments);
421 NILFS_SEGMENTS_RO_ATTR(README);
422 
423 static struct attribute *nilfs_segments_attrs[] = {
424 	NILFS_SEGMENTS_ATTR_LIST(segments_number),
425 	NILFS_SEGMENTS_ATTR_LIST(blocks_per_segment),
426 	NILFS_SEGMENTS_ATTR_LIST(clean_segments),
427 	NILFS_SEGMENTS_ATTR_LIST(dirty_segments),
428 	NILFS_SEGMENTS_ATTR_LIST(README),
429 	NULL,
430 };
431 
432 NILFS_DEV_INT_GROUP_OPS(segments, dev);
433 NILFS_DEV_INT_GROUP_TYPE(segments, dev);
434 NILFS_DEV_INT_GROUP_FNS(segments, dev);
435 
436 /************************************************************************
437  *                        NILFS segctor attrs                           *
438  ************************************************************************/
439 
440 static ssize_t
441 nilfs_segctor_last_pseg_block_show(struct nilfs_segctor_attr *attr,
442 				    struct the_nilfs *nilfs,
443 				    char *buf)
444 {
445 	sector_t last_pseg;
446 
447 	spin_lock(&nilfs->ns_last_segment_lock);
448 	last_pseg = nilfs->ns_last_pseg;
449 	spin_unlock(&nilfs->ns_last_segment_lock);
450 
451 	return snprintf(buf, PAGE_SIZE, "%llu\n",
452 			(unsigned long long)last_pseg);
453 }
454 
455 static ssize_t
456 nilfs_segctor_last_seg_sequence_show(struct nilfs_segctor_attr *attr,
457 					struct the_nilfs *nilfs,
458 					char *buf)
459 {
460 	u64 last_seq;
461 
462 	spin_lock(&nilfs->ns_last_segment_lock);
463 	last_seq = nilfs->ns_last_seq;
464 	spin_unlock(&nilfs->ns_last_segment_lock);
465 
466 	return snprintf(buf, PAGE_SIZE, "%llu\n", last_seq);
467 }
468 
469 static ssize_t
470 nilfs_segctor_last_seg_checkpoint_show(struct nilfs_segctor_attr *attr,
471 					struct the_nilfs *nilfs,
472 					char *buf)
473 {
474 	__u64 last_cno;
475 
476 	spin_lock(&nilfs->ns_last_segment_lock);
477 	last_cno = nilfs->ns_last_cno;
478 	spin_unlock(&nilfs->ns_last_segment_lock);
479 
480 	return snprintf(buf, PAGE_SIZE, "%llu\n", last_cno);
481 }
482 
483 static ssize_t
484 nilfs_segctor_current_seg_sequence_show(struct nilfs_segctor_attr *attr,
485 					struct the_nilfs *nilfs,
486 					char *buf)
487 {
488 	u64 seg_seq;
489 
490 	down_read(&nilfs->ns_segctor_sem);
491 	seg_seq = nilfs->ns_seg_seq;
492 	up_read(&nilfs->ns_segctor_sem);
493 
494 	return snprintf(buf, PAGE_SIZE, "%llu\n", seg_seq);
495 }
496 
497 static ssize_t
498 nilfs_segctor_current_last_full_seg_show(struct nilfs_segctor_attr *attr,
499 					 struct the_nilfs *nilfs,
500 					 char *buf)
501 {
502 	__u64 segnum;
503 
504 	down_read(&nilfs->ns_segctor_sem);
505 	segnum = nilfs->ns_segnum;
506 	up_read(&nilfs->ns_segctor_sem);
507 
508 	return snprintf(buf, PAGE_SIZE, "%llu\n", segnum);
509 }
510 
511 static ssize_t
512 nilfs_segctor_next_full_seg_show(struct nilfs_segctor_attr *attr,
513 				 struct the_nilfs *nilfs,
514 				 char *buf)
515 {
516 	__u64 nextnum;
517 
518 	down_read(&nilfs->ns_segctor_sem);
519 	nextnum = nilfs->ns_nextnum;
520 	up_read(&nilfs->ns_segctor_sem);
521 
522 	return snprintf(buf, PAGE_SIZE, "%llu\n", nextnum);
523 }
524 
525 static ssize_t
526 nilfs_segctor_next_pseg_offset_show(struct nilfs_segctor_attr *attr,
527 					struct the_nilfs *nilfs,
528 					char *buf)
529 {
530 	unsigned long pseg_offset;
531 
532 	down_read(&nilfs->ns_segctor_sem);
533 	pseg_offset = nilfs->ns_pseg_offset;
534 	up_read(&nilfs->ns_segctor_sem);
535 
536 	return snprintf(buf, PAGE_SIZE, "%lu\n", pseg_offset);
537 }
538 
539 static ssize_t
540 nilfs_segctor_next_checkpoint_show(struct nilfs_segctor_attr *attr,
541 					struct the_nilfs *nilfs,
542 					char *buf)
543 {
544 	__u64 cno;
545 
546 	down_read(&nilfs->ns_segctor_sem);
547 	cno = nilfs->ns_cno;
548 	up_read(&nilfs->ns_segctor_sem);
549 
550 	return snprintf(buf, PAGE_SIZE, "%llu\n", cno);
551 }
552 
553 static ssize_t
554 nilfs_segctor_last_seg_write_time_show(struct nilfs_segctor_attr *attr,
555 					struct the_nilfs *nilfs,
556 					char *buf)
557 {
558 	time64_t ctime;
559 
560 	down_read(&nilfs->ns_segctor_sem);
561 	ctime = nilfs->ns_ctime;
562 	up_read(&nilfs->ns_segctor_sem);
563 
564 	return sysfs_emit(buf, "%ptTs\n", &ctime);
565 }
566 
567 static ssize_t
568 nilfs_segctor_last_seg_write_time_secs_show(struct nilfs_segctor_attr *attr,
569 					    struct the_nilfs *nilfs,
570 					    char *buf)
571 {
572 	time64_t ctime;
573 
574 	down_read(&nilfs->ns_segctor_sem);
575 	ctime = nilfs->ns_ctime;
576 	up_read(&nilfs->ns_segctor_sem);
577 
578 	return snprintf(buf, PAGE_SIZE, "%llu\n", ctime);
579 }
580 
581 static ssize_t
582 nilfs_segctor_last_nongc_write_time_show(struct nilfs_segctor_attr *attr,
583 					 struct the_nilfs *nilfs,
584 					 char *buf)
585 {
586 	time64_t nongc_ctime;
587 
588 	down_read(&nilfs->ns_segctor_sem);
589 	nongc_ctime = nilfs->ns_nongc_ctime;
590 	up_read(&nilfs->ns_segctor_sem);
591 
592 	return sysfs_emit(buf, "%ptTs\n", &nongc_ctime);
593 }
594 
595 static ssize_t
596 nilfs_segctor_last_nongc_write_time_secs_show(struct nilfs_segctor_attr *attr,
597 						struct the_nilfs *nilfs,
598 						char *buf)
599 {
600 	time64_t nongc_ctime;
601 
602 	down_read(&nilfs->ns_segctor_sem);
603 	nongc_ctime = nilfs->ns_nongc_ctime;
604 	up_read(&nilfs->ns_segctor_sem);
605 
606 	return snprintf(buf, PAGE_SIZE, "%llu\n", nongc_ctime);
607 }
608 
609 static ssize_t
610 nilfs_segctor_dirty_data_blocks_count_show(struct nilfs_segctor_attr *attr,
611 					    struct the_nilfs *nilfs,
612 					    char *buf)
613 {
614 	u32 ndirtyblks;
615 
616 	down_read(&nilfs->ns_segctor_sem);
617 	ndirtyblks = atomic_read(&nilfs->ns_ndirtyblks);
618 	up_read(&nilfs->ns_segctor_sem);
619 
620 	return snprintf(buf, PAGE_SIZE, "%u\n", ndirtyblks);
621 }
622 
623 static const char segctor_readme_str[] =
624 	"The segctor group contains attributes that describe\n"
625 	"segctor thread activity details.\n\n"
626 	"(1) last_pseg_block\n"
627 	"\tshow start block number of the latest segment.\n\n"
628 	"(2) last_seg_sequence\n"
629 	"\tshow sequence value of the latest segment.\n\n"
630 	"(3) last_seg_checkpoint\n"
631 	"\tshow checkpoint number of the latest segment.\n\n"
632 	"(4) current_seg_sequence\n\tshow segment sequence counter.\n\n"
633 	"(5) current_last_full_seg\n"
634 	"\tshow index number of the latest full segment.\n\n"
635 	"(6) next_full_seg\n"
636 	"\tshow index number of the full segment index to be used next.\n\n"
637 	"(7) next_pseg_offset\n"
638 	"\tshow offset of next partial segment in the current full segment.\n\n"
639 	"(8) next_checkpoint\n\tshow next checkpoint number.\n\n"
640 	"(9) last_seg_write_time\n"
641 	"\tshow write time of the last segment in human-readable format.\n\n"
642 	"(10) last_seg_write_time_secs\n"
643 	"\tshow write time of the last segment in seconds.\n\n"
644 	"(11) last_nongc_write_time\n"
645 	"\tshow write time of the last segment not for cleaner operation "
646 	"in human-readable format.\n\n"
647 	"(12) last_nongc_write_time_secs\n"
648 	"\tshow write time of the last segment not for cleaner operation "
649 	"in seconds.\n\n"
650 	"(13) dirty_data_blocks_count\n"
651 	"\tshow number of dirty data blocks.\n\n";
652 
653 static ssize_t
654 nilfs_segctor_README_show(struct nilfs_segctor_attr *attr,
655 			  struct the_nilfs *nilfs, char *buf)
656 {
657 	return snprintf(buf, PAGE_SIZE, segctor_readme_str);
658 }
659 
660 NILFS_SEGCTOR_RO_ATTR(last_pseg_block);
661 NILFS_SEGCTOR_RO_ATTR(last_seg_sequence);
662 NILFS_SEGCTOR_RO_ATTR(last_seg_checkpoint);
663 NILFS_SEGCTOR_RO_ATTR(current_seg_sequence);
664 NILFS_SEGCTOR_RO_ATTR(current_last_full_seg);
665 NILFS_SEGCTOR_RO_ATTR(next_full_seg);
666 NILFS_SEGCTOR_RO_ATTR(next_pseg_offset);
667 NILFS_SEGCTOR_RO_ATTR(next_checkpoint);
668 NILFS_SEGCTOR_RO_ATTR(last_seg_write_time);
669 NILFS_SEGCTOR_RO_ATTR(last_seg_write_time_secs);
670 NILFS_SEGCTOR_RO_ATTR(last_nongc_write_time);
671 NILFS_SEGCTOR_RO_ATTR(last_nongc_write_time_secs);
672 NILFS_SEGCTOR_RO_ATTR(dirty_data_blocks_count);
673 NILFS_SEGCTOR_RO_ATTR(README);
674 
675 static struct attribute *nilfs_segctor_attrs[] = {
676 	NILFS_SEGCTOR_ATTR_LIST(last_pseg_block),
677 	NILFS_SEGCTOR_ATTR_LIST(last_seg_sequence),
678 	NILFS_SEGCTOR_ATTR_LIST(last_seg_checkpoint),
679 	NILFS_SEGCTOR_ATTR_LIST(current_seg_sequence),
680 	NILFS_SEGCTOR_ATTR_LIST(current_last_full_seg),
681 	NILFS_SEGCTOR_ATTR_LIST(next_full_seg),
682 	NILFS_SEGCTOR_ATTR_LIST(next_pseg_offset),
683 	NILFS_SEGCTOR_ATTR_LIST(next_checkpoint),
684 	NILFS_SEGCTOR_ATTR_LIST(last_seg_write_time),
685 	NILFS_SEGCTOR_ATTR_LIST(last_seg_write_time_secs),
686 	NILFS_SEGCTOR_ATTR_LIST(last_nongc_write_time),
687 	NILFS_SEGCTOR_ATTR_LIST(last_nongc_write_time_secs),
688 	NILFS_SEGCTOR_ATTR_LIST(dirty_data_blocks_count),
689 	NILFS_SEGCTOR_ATTR_LIST(README),
690 	NULL,
691 };
692 
693 NILFS_DEV_INT_GROUP_OPS(segctor, dev);
694 NILFS_DEV_INT_GROUP_TYPE(segctor, dev);
695 NILFS_DEV_INT_GROUP_FNS(segctor, dev);
696 
697 /************************************************************************
698  *                        NILFS superblock attrs                        *
699  ************************************************************************/
700 
701 static ssize_t
702 nilfs_superblock_sb_write_time_show(struct nilfs_superblock_attr *attr,
703 				     struct the_nilfs *nilfs,
704 				     char *buf)
705 {
706 	time64_t sbwtime;
707 
708 	down_read(&nilfs->ns_sem);
709 	sbwtime = nilfs->ns_sbwtime;
710 	up_read(&nilfs->ns_sem);
711 
712 	return sysfs_emit(buf, "%ptTs\n", &sbwtime);
713 }
714 
715 static ssize_t
716 nilfs_superblock_sb_write_time_secs_show(struct nilfs_superblock_attr *attr,
717 					 struct the_nilfs *nilfs,
718 					 char *buf)
719 {
720 	time64_t sbwtime;
721 
722 	down_read(&nilfs->ns_sem);
723 	sbwtime = nilfs->ns_sbwtime;
724 	up_read(&nilfs->ns_sem);
725 
726 	return snprintf(buf, PAGE_SIZE, "%llu\n", sbwtime);
727 }
728 
729 static ssize_t
730 nilfs_superblock_sb_write_count_show(struct nilfs_superblock_attr *attr,
731 				      struct the_nilfs *nilfs,
732 				      char *buf)
733 {
734 	unsigned int sbwcount;
735 
736 	down_read(&nilfs->ns_sem);
737 	sbwcount = nilfs->ns_sbwcount;
738 	up_read(&nilfs->ns_sem);
739 
740 	return snprintf(buf, PAGE_SIZE, "%u\n", sbwcount);
741 }
742 
743 static ssize_t
744 nilfs_superblock_sb_update_frequency_show(struct nilfs_superblock_attr *attr,
745 					    struct the_nilfs *nilfs,
746 					    char *buf)
747 {
748 	unsigned int sb_update_freq;
749 
750 	down_read(&nilfs->ns_sem);
751 	sb_update_freq = nilfs->ns_sb_update_freq;
752 	up_read(&nilfs->ns_sem);
753 
754 	return snprintf(buf, PAGE_SIZE, "%u\n", sb_update_freq);
755 }
756 
757 static ssize_t
758 nilfs_superblock_sb_update_frequency_store(struct nilfs_superblock_attr *attr,
759 					    struct the_nilfs *nilfs,
760 					    const char *buf, size_t count)
761 {
762 	unsigned int val;
763 	int err;
764 
765 	err = kstrtouint(skip_spaces(buf), 0, &val);
766 	if (err) {
767 		nilfs_err(nilfs->ns_sb, "unable to convert string: err=%d",
768 			  err);
769 		return err;
770 	}
771 
772 	if (val < NILFS_SB_FREQ) {
773 		val = NILFS_SB_FREQ;
774 		nilfs_warn(nilfs->ns_sb,
775 			   "superblock update frequency cannot be lesser than 10 seconds");
776 	}
777 
778 	down_write(&nilfs->ns_sem);
779 	nilfs->ns_sb_update_freq = val;
780 	up_write(&nilfs->ns_sem);
781 
782 	return count;
783 }
784 
785 static const char sb_readme_str[] =
786 	"The superblock group contains attributes that describe\n"
787 	"superblock's details.\n\n"
788 	"(1) sb_write_time\n\tshow previous write time of super block "
789 	"in human-readable format.\n\n"
790 	"(2) sb_write_time_secs\n\tshow previous write time of super block "
791 	"in seconds.\n\n"
792 	"(3) sb_write_count\n\tshow write count of super block.\n\n"
793 	"(4) sb_update_frequency\n"
794 	"\tshow/set interval of periodical update of superblock (in seconds).\n\n"
795 	"\tYou can set preferable frequency of superblock update by command:\n\n"
796 	"\t'echo <val> > /sys/fs/<nilfs>/<dev>/superblock/sb_update_frequency'\n";
797 
798 static ssize_t
799 nilfs_superblock_README_show(struct nilfs_superblock_attr *attr,
800 				struct the_nilfs *nilfs, char *buf)
801 {
802 	return snprintf(buf, PAGE_SIZE, sb_readme_str);
803 }
804 
805 NILFS_SUPERBLOCK_RO_ATTR(sb_write_time);
806 NILFS_SUPERBLOCK_RO_ATTR(sb_write_time_secs);
807 NILFS_SUPERBLOCK_RO_ATTR(sb_write_count);
808 NILFS_SUPERBLOCK_RW_ATTR(sb_update_frequency);
809 NILFS_SUPERBLOCK_RO_ATTR(README);
810 
811 static struct attribute *nilfs_superblock_attrs[] = {
812 	NILFS_SUPERBLOCK_ATTR_LIST(sb_write_time),
813 	NILFS_SUPERBLOCK_ATTR_LIST(sb_write_time_secs),
814 	NILFS_SUPERBLOCK_ATTR_LIST(sb_write_count),
815 	NILFS_SUPERBLOCK_ATTR_LIST(sb_update_frequency),
816 	NILFS_SUPERBLOCK_ATTR_LIST(README),
817 	NULL,
818 };
819 
820 NILFS_DEV_INT_GROUP_OPS(superblock, dev);
821 NILFS_DEV_INT_GROUP_TYPE(superblock, dev);
822 NILFS_DEV_INT_GROUP_FNS(superblock, dev);
823 
824 /************************************************************************
825  *                        NILFS device attrs                            *
826  ************************************************************************/
827 
828 static
829 ssize_t nilfs_dev_revision_show(struct nilfs_dev_attr *attr,
830 				struct the_nilfs *nilfs,
831 				char *buf)
832 {
833 	struct nilfs_super_block **sbp = nilfs->ns_sbp;
834 	u32 major = le32_to_cpu(sbp[0]->s_rev_level);
835 	u16 minor = le16_to_cpu(sbp[0]->s_minor_rev_level);
836 
837 	return snprintf(buf, PAGE_SIZE, "%d.%d\n", major, minor);
838 }
839 
840 static
841 ssize_t nilfs_dev_blocksize_show(struct nilfs_dev_attr *attr,
842 				 struct the_nilfs *nilfs,
843 				 char *buf)
844 {
845 	return snprintf(buf, PAGE_SIZE, "%u\n", nilfs->ns_blocksize);
846 }
847 
848 static
849 ssize_t nilfs_dev_device_size_show(struct nilfs_dev_attr *attr,
850 				    struct the_nilfs *nilfs,
851 				    char *buf)
852 {
853 	struct nilfs_super_block **sbp = nilfs->ns_sbp;
854 	u64 dev_size = le64_to_cpu(sbp[0]->s_dev_size);
855 
856 	return snprintf(buf, PAGE_SIZE, "%llu\n", dev_size);
857 }
858 
859 static
860 ssize_t nilfs_dev_free_blocks_show(struct nilfs_dev_attr *attr,
861 				   struct the_nilfs *nilfs,
862 				   char *buf)
863 {
864 	sector_t free_blocks = 0;
865 
866 	nilfs_count_free_blocks(nilfs, &free_blocks);
867 	return snprintf(buf, PAGE_SIZE, "%llu\n",
868 			(unsigned long long)free_blocks);
869 }
870 
871 static
872 ssize_t nilfs_dev_uuid_show(struct nilfs_dev_attr *attr,
873 			    struct the_nilfs *nilfs,
874 			    char *buf)
875 {
876 	struct nilfs_super_block **sbp = nilfs->ns_sbp;
877 
878 	return snprintf(buf, PAGE_SIZE, "%pUb\n", sbp[0]->s_uuid);
879 }
880 
881 static
882 ssize_t nilfs_dev_volume_name_show(struct nilfs_dev_attr *attr,
883 				    struct the_nilfs *nilfs,
884 				    char *buf)
885 {
886 	struct nilfs_super_block **sbp = nilfs->ns_sbp;
887 
888 	return scnprintf(buf, sizeof(sbp[0]->s_volume_name), "%s\n",
889 			 sbp[0]->s_volume_name);
890 }
891 
892 static const char dev_readme_str[] =
893 	"The <device> group contains attributes that describe file system\n"
894 	"partition's details.\n\n"
895 	"(1) revision\n\tshow NILFS file system revision.\n\n"
896 	"(2) blocksize\n\tshow volume block size in bytes.\n\n"
897 	"(3) device_size\n\tshow volume size in bytes.\n\n"
898 	"(4) free_blocks\n\tshow count of free blocks on volume.\n\n"
899 	"(5) uuid\n\tshow volume's UUID.\n\n"
900 	"(6) volume_name\n\tshow volume's name.\n\n";
901 
902 static ssize_t nilfs_dev_README_show(struct nilfs_dev_attr *attr,
903 				     struct the_nilfs *nilfs,
904 				     char *buf)
905 {
906 	return snprintf(buf, PAGE_SIZE, dev_readme_str);
907 }
908 
909 NILFS_DEV_RO_ATTR(revision);
910 NILFS_DEV_RO_ATTR(blocksize);
911 NILFS_DEV_RO_ATTR(device_size);
912 NILFS_DEV_RO_ATTR(free_blocks);
913 NILFS_DEV_RO_ATTR(uuid);
914 NILFS_DEV_RO_ATTR(volume_name);
915 NILFS_DEV_RO_ATTR(README);
916 
917 static struct attribute *nilfs_dev_attrs[] = {
918 	NILFS_DEV_ATTR_LIST(revision),
919 	NILFS_DEV_ATTR_LIST(blocksize),
920 	NILFS_DEV_ATTR_LIST(device_size),
921 	NILFS_DEV_ATTR_LIST(free_blocks),
922 	NILFS_DEV_ATTR_LIST(uuid),
923 	NILFS_DEV_ATTR_LIST(volume_name),
924 	NILFS_DEV_ATTR_LIST(README),
925 	NULL,
926 };
927 
928 static ssize_t nilfs_dev_attr_show(struct kobject *kobj,
929 				    struct attribute *attr, char *buf)
930 {
931 	struct the_nilfs *nilfs = container_of(kobj, struct the_nilfs,
932 						ns_dev_kobj);
933 	struct nilfs_dev_attr *a = container_of(attr, struct nilfs_dev_attr,
934 						attr);
935 
936 	return a->show ? a->show(a, nilfs, buf) : 0;
937 }
938 
939 static ssize_t nilfs_dev_attr_store(struct kobject *kobj,
940 				    struct attribute *attr,
941 				    const char *buf, size_t len)
942 {
943 	struct the_nilfs *nilfs = container_of(kobj, struct the_nilfs,
944 						ns_dev_kobj);
945 	struct nilfs_dev_attr *a = container_of(attr, struct nilfs_dev_attr,
946 						attr);
947 
948 	return a->store ? a->store(a, nilfs, buf, len) : 0;
949 }
950 
951 static void nilfs_dev_attr_release(struct kobject *kobj)
952 {
953 	struct the_nilfs *nilfs = container_of(kobj, struct the_nilfs,
954 						ns_dev_kobj);
955 	complete(&nilfs->ns_dev_kobj_unregister);
956 }
957 
958 static const struct sysfs_ops nilfs_dev_attr_ops = {
959 	.show	= nilfs_dev_attr_show,
960 	.store	= nilfs_dev_attr_store,
961 };
962 
963 static struct kobj_type nilfs_dev_ktype = {
964 	.default_attrs	= nilfs_dev_attrs,
965 	.sysfs_ops	= &nilfs_dev_attr_ops,
966 	.release	= nilfs_dev_attr_release,
967 };
968 
969 int nilfs_sysfs_create_device_group(struct super_block *sb)
970 {
971 	struct the_nilfs *nilfs = sb->s_fs_info;
972 	size_t devgrp_size = sizeof(struct nilfs_sysfs_dev_subgroups);
973 	int err;
974 
975 	nilfs->ns_dev_subgroups = kzalloc(devgrp_size, GFP_KERNEL);
976 	if (unlikely(!nilfs->ns_dev_subgroups)) {
977 		err = -ENOMEM;
978 		nilfs_err(sb, "unable to allocate memory for device group");
979 		goto failed_create_device_group;
980 	}
981 
982 	nilfs->ns_dev_kobj.kset = nilfs_kset;
983 	init_completion(&nilfs->ns_dev_kobj_unregister);
984 	err = kobject_init_and_add(&nilfs->ns_dev_kobj, &nilfs_dev_ktype, NULL,
985 				    "%s", sb->s_id);
986 	if (err)
987 		goto cleanup_dev_kobject;
988 
989 	err = nilfs_sysfs_create_mounted_snapshots_group(nilfs);
990 	if (err)
991 		goto cleanup_dev_kobject;
992 
993 	err = nilfs_sysfs_create_checkpoints_group(nilfs);
994 	if (err)
995 		goto delete_mounted_snapshots_group;
996 
997 	err = nilfs_sysfs_create_segments_group(nilfs);
998 	if (err)
999 		goto delete_checkpoints_group;
1000 
1001 	err = nilfs_sysfs_create_superblock_group(nilfs);
1002 	if (err)
1003 		goto delete_segments_group;
1004 
1005 	err = nilfs_sysfs_create_segctor_group(nilfs);
1006 	if (err)
1007 		goto delete_superblock_group;
1008 
1009 	return 0;
1010 
1011 delete_superblock_group:
1012 	nilfs_sysfs_delete_superblock_group(nilfs);
1013 
1014 delete_segments_group:
1015 	nilfs_sysfs_delete_segments_group(nilfs);
1016 
1017 delete_checkpoints_group:
1018 	nilfs_sysfs_delete_checkpoints_group(nilfs);
1019 
1020 delete_mounted_snapshots_group:
1021 	nilfs_sysfs_delete_mounted_snapshots_group(nilfs);
1022 
1023 cleanup_dev_kobject:
1024 	kobject_put(&nilfs->ns_dev_kobj);
1025 	kfree(nilfs->ns_dev_subgroups);
1026 
1027 failed_create_device_group:
1028 	return err;
1029 }
1030 
1031 void nilfs_sysfs_delete_device_group(struct the_nilfs *nilfs)
1032 {
1033 	nilfs_sysfs_delete_mounted_snapshots_group(nilfs);
1034 	nilfs_sysfs_delete_checkpoints_group(nilfs);
1035 	nilfs_sysfs_delete_segments_group(nilfs);
1036 	nilfs_sysfs_delete_superblock_group(nilfs);
1037 	nilfs_sysfs_delete_segctor_group(nilfs);
1038 	kobject_del(&nilfs->ns_dev_kobj);
1039 	kobject_put(&nilfs->ns_dev_kobj);
1040 	kfree(nilfs->ns_dev_subgroups);
1041 }
1042 
1043 /************************************************************************
1044  *                        NILFS feature attrs                           *
1045  ************************************************************************/
1046 
1047 static ssize_t nilfs_feature_revision_show(struct kobject *kobj,
1048 					    struct attribute *attr, char *buf)
1049 {
1050 	return snprintf(buf, PAGE_SIZE, "%d.%d\n",
1051 			NILFS_CURRENT_REV, NILFS_MINOR_REV);
1052 }
1053 
1054 static const char features_readme_str[] =
1055 	"The features group contains attributes that describe NILFS file\n"
1056 	"system driver features.\n\n"
1057 	"(1) revision\n\tshow current revision of NILFS file system driver.\n";
1058 
1059 static ssize_t nilfs_feature_README_show(struct kobject *kobj,
1060 					 struct attribute *attr,
1061 					 char *buf)
1062 {
1063 	return snprintf(buf, PAGE_SIZE, features_readme_str);
1064 }
1065 
1066 NILFS_FEATURE_RO_ATTR(revision);
1067 NILFS_FEATURE_RO_ATTR(README);
1068 
1069 static struct attribute *nilfs_feature_attrs[] = {
1070 	NILFS_FEATURE_ATTR_LIST(revision),
1071 	NILFS_FEATURE_ATTR_LIST(README),
1072 	NULL,
1073 };
1074 
1075 static const struct attribute_group nilfs_feature_attr_group = {
1076 	.name = "features",
1077 	.attrs = nilfs_feature_attrs,
1078 };
1079 
1080 int __init nilfs_sysfs_init(void)
1081 {
1082 	int err;
1083 
1084 	nilfs_kset = kset_create_and_add(NILFS_ROOT_GROUP_NAME, NULL, fs_kobj);
1085 	if (!nilfs_kset) {
1086 		err = -ENOMEM;
1087 		nilfs_err(NULL, "unable to create sysfs entry: err=%d", err);
1088 		goto failed_sysfs_init;
1089 	}
1090 
1091 	err = sysfs_create_group(&nilfs_kset->kobj, &nilfs_feature_attr_group);
1092 	if (unlikely(err)) {
1093 		nilfs_err(NULL, "unable to create feature group: err=%d", err);
1094 		goto cleanup_sysfs_init;
1095 	}
1096 
1097 	return 0;
1098 
1099 cleanup_sysfs_init:
1100 	kset_unregister(nilfs_kset);
1101 
1102 failed_sysfs_init:
1103 	return err;
1104 }
1105 
1106 void nilfs_sysfs_exit(void)
1107 {
1108 	sysfs_remove_group(&nilfs_kset->kobj, &nilfs_feature_attr_group);
1109 	kset_unregister(nilfs_kset);
1110 }
1111