fs/nilfs2/sysfs.c

   1 /*
   2  * sysfs.c - sysfs support implementation.
   3  *
   4  * Copyright (C) 2005-2014 Nippon Telegraph and Telephone Corporation.
   5  * Copyright (C) 2014 HGST, Inc., a Western Digital Company.
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * Written by Vyacheslav Dubeyko <Vyacheslav.Dubeyko@hgst.com>
  18  */
  19
  20 #include <linux/kobject.h>
  21
  22 #include "nilfs.h"
  23 #include "mdt.h"
  24 #include "sufile.h"
  25 #include "cpfile.h"
  26 #include "sysfs.h"
  27
  28 /* /sys/fs/<nilfs>/ */
  29 static struct kset *nilfs_kset;
  30
  31 #define NILFS_SHOW_TIME(time_t_val, buf) ({ \
  32                 struct tm res; \
  33                 int count = 0; \
  34                 time64_to_tm(time_t_val, 0, &res); \
  35                 res.tm_year += 1900; \
  36                 res.tm_mon += 1; \
  37                 count = scnprintf(buf, PAGE_SIZE, \
  38                                     "%ld-%.2d-%.2d %.2d:%.2d:%.2d\n", \
  39                                     res.tm_year, res.tm_mon, res.tm_mday, \
  40                                     res.tm_hour, res.tm_min, res.tm_sec);\
  41                 count; \
  42 })
  43
  44 #define NILFS_DEV_INT_GROUP_OPS(name, parent_name) \
  45 static ssize_t nilfs_##name##_attr_show(struct kobject *kobj, \
  46                                         struct attribute *attr, char *buf) \
  47 { \
  48         struct the_nilfs *nilfs = container_of(kobj->parent, \
  49                                                 struct the_nilfs, \
  50                                                 ns_##parent_name##_kobj); \
  51         struct nilfs_##name##_attr *a = container_of(attr, \
  52                                                 struct nilfs_##name##_attr, \
  53                                                 attr); \
  54         return a->show ? a->show(a, nilfs, buf) : 0; \
  55 } \
  56 static ssize_t nilfs_##name##_attr_store(struct kobject *kobj, \
  57                                          struct attribute *attr, \
  58                                          const char *buf, size_t len) \
  59 { \
  60         struct the_nilfs *nilfs = container_of(kobj->parent, \
  61                                                 struct the_nilfs, \
  62                                                 ns_##parent_name##_kobj); \
  63         struct nilfs_##name##_attr *a = container_of(attr, \
  64                                                 struct nilfs_##name##_attr, \
  65                                                 attr); \
  66         return a->store ? a->store(a, nilfs, buf, len) : 0; \
  67 } \
  68 static const struct sysfs_ops nilfs_##name##_attr_ops = { \
  69         .show   = nilfs_##name##_attr_show, \
  70         .store  = nilfs_##name##_attr_store, \
  71 }
  72
  73 #define NILFS_DEV_INT_GROUP_TYPE(name, parent_name) \
  74 static void nilfs_##name##_attr_release(struct kobject *kobj) \
  75 { \
  76         struct nilfs_sysfs_##parent_name##_subgroups *subgroups; \
  77         struct the_nilfs *nilfs = container_of(kobj->parent, \
  78                                                 struct the_nilfs, \
  79                                                 ns_##parent_name##_kobj); \
  80         subgroups = nilfs->ns_##parent_name##_subgroups; \
  81         complete(&subgroups->sg_##name##_kobj_unregister); \
  82 } \
  83 static struct kobj_type nilfs_##name##_ktype = { \
  84         .default_attrs  = nilfs_##name##_attrs, \
  85         .sysfs_ops      = &nilfs_##name##_attr_ops, \
  86         .release        = nilfs_##name##_attr_release, \
  87 }
  88
  89 #define NILFS_DEV_INT_GROUP_FNS(name, parent_name) \
  90 static int nilfs_sysfs_create_##name##_group(struct the_nilfs *nilfs) \
  91 { \
  92         struct kobject *parent; \
  93         struct kobject *kobj; \
  94         struct completion *kobj_unregister; \
  95         struct nilfs_sysfs_##parent_name##_subgroups *subgroups; \
  96         int err; \
  97         subgroups = nilfs->ns_##parent_name##_subgroups; \
  98         kobj = &subgroups->sg_##name##_kobj; \
  99         kobj_unregister = &subgroups->sg_##name##_kobj_unregister; \
 100         parent = &nilfs->ns_##parent_name##_kobj; \
 101         kobj->kset = nilfs_kset; \
 102         init_completion(kobj_unregister); \
 103         err = kobject_init_and_add(kobj, &nilfs_##name##_ktype, parent, \
 104                                     #name); \
 105         if (err) \
 106                 return err; \
 107         return 0; \
 108 } \
 109 static void nilfs_sysfs_delete_##name##_group(struct the_nilfs *nilfs) \
 110 { \
 111         kobject_del(&nilfs->ns_##parent_name##_subgroups->sg_##name##_kobj); \
 112 }
 113
 114 /************************************************************************
 115  *                        NILFS snapshot attrs                          *
 116  ************************************************************************/
 117
 118 static ssize_t
 119 nilfs_snapshot_inodes_count_show(struct nilfs_snapshot_attr *attr,
 120                                  struct nilfs_root *root, char *buf)
 121 {
 122         return snprintf(buf, PAGE_SIZE, "%llu\n",
 123                         (unsigned long long)atomic64_read(&root->inodes_count));
 124 }
 125
 126 static ssize_t
 127 nilfs_snapshot_blocks_count_show(struct nilfs_snapshot_attr *attr,
 128                                  struct nilfs_root *root, char *buf)
 129 {
 130         return snprintf(buf, PAGE_SIZE, "%llu\n",
 131                         (unsigned long long)atomic64_read(&root->blocks_count));
 132 }
 133
 134 static const char snapshot_readme_str[] =
 135         "The group contains details about mounted snapshot.\n\n"
 136         "(1) inodes_count\n\tshow number of inodes for snapshot.\n\n"
 137         "(2) blocks_count\n\tshow number of blocks for snapshot.\n\n";
 138
 139 static ssize_t
 140 nilfs_snapshot_README_show(struct nilfs_snapshot_attr *attr,
 141                             struct nilfs_root *root, char *buf)
 142 {
 143         return snprintf(buf, PAGE_SIZE, snapshot_readme_str);
 144 }
 145
 146 NILFS_SNAPSHOT_RO_ATTR(inodes_count);
 147 NILFS_SNAPSHOT_RO_ATTR(blocks_count);
 148 NILFS_SNAPSHOT_RO_ATTR(README);
 149
 150 static struct attribute *nilfs_snapshot_attrs[] = {
 151         NILFS_SNAPSHOT_ATTR_LIST(inodes_count),
 152         NILFS_SNAPSHOT_ATTR_LIST(blocks_count),
 153         NILFS_SNAPSHOT_ATTR_LIST(README),
 154         NULL,
 155 };
 156
 157 static ssize_t nilfs_snapshot_attr_show(struct kobject *kobj,
 158                                         struct attribute *attr, char *buf)
 159 {
 160         struct nilfs_root *root =
 161                         container_of(kobj, struct nilfs_root, snapshot_kobj);
 162         struct nilfs_snapshot_attr *a =
 163                         container_of(attr, struct nilfs_snapshot_attr, attr);
 164
 165         return a->show ? a->show(a, root, buf) : 0;
 166 }
 167
 168 static ssize_t nilfs_snapshot_attr_store(struct kobject *kobj,
 169                                          struct attribute *attr,
 170                                          const char *buf, size_t len)
 171 {
 172         struct nilfs_root *root =
 173                         container_of(kobj, struct nilfs_root, snapshot_kobj);
 174         struct nilfs_snapshot_attr *a =
 175                         container_of(attr, struct nilfs_snapshot_attr, attr);
 176
 177         return a->store ? a->store(a, root, buf, len) : 0;
 178 }
 179
 180 static void nilfs_snapshot_attr_release(struct kobject *kobj)
 181 {
 182         struct nilfs_root *root = container_of(kobj, struct nilfs_root,
 183                                                 snapshot_kobj);
 184         complete(&root->snapshot_kobj_unregister);
 185 }
 186
 187 static const struct sysfs_ops nilfs_snapshot_attr_ops = {
 188         .show   = nilfs_snapshot_attr_show,
 189         .store  = nilfs_snapshot_attr_store,
 190 };
 191
 192 static struct kobj_type nilfs_snapshot_ktype = {
 193         .default_attrs  = nilfs_snapshot_attrs,
 194         .sysfs_ops      = &nilfs_snapshot_attr_ops,
 195         .release        = nilfs_snapshot_attr_release,
 196 };
 197
 198 int nilfs_sysfs_create_snapshot_group(struct nilfs_root *root)
 199 {
 200         struct the_nilfs *nilfs;
 201         struct kobject *parent;
 202         int err;
 203
 204         nilfs = root->nilfs;
 205         parent = &nilfs->ns_dev_subgroups->sg_mounted_snapshots_kobj;
 206         root->snapshot_kobj.kset = nilfs_kset;
 207         init_completion(&root->snapshot_kobj_unregister);
 208
 209         if (root->cno == NILFS_CPTREE_CURRENT_CNO) {
 210                 err = kobject_init_and_add(&root->snapshot_kobj,
 211                                             &nilfs_snapshot_ktype,
 212                                             &nilfs->ns_dev_kobj,
 213                                             "current_checkpoint");
 214         } else {
 215                 err = kobject_init_and_add(&root->snapshot_kobj,
 216                                             &nilfs_snapshot_ktype,
 217                                             parent,
 218                                             "%llu", root->cno);
 219         }
 220
 221         if (err)
 222                 return err;
 223
 224         return 0;
 225 }
 226
 227 void nilfs_sysfs_delete_snapshot_group(struct nilfs_root *root)
 228 {
 229         kobject_del(&root->snapshot_kobj);
 230 }
 231
 232 /************************************************************************
 233  *                    NILFS mounted snapshots attrs                     *
 234  ************************************************************************/
 235
 236 static const char mounted_snapshots_readme_str[] =
 237         "The mounted_snapshots group contains group for\n"
 238         "every mounted snapshot.\n";
 239
 240 static ssize_t
 241 nilfs_mounted_snapshots_README_show(struct nilfs_mounted_snapshots_attr *attr,
 242                                     struct the_nilfs *nilfs, char *buf)
 243 {
 244         return snprintf(buf, PAGE_SIZE, mounted_snapshots_readme_str);
 245 }
 246
 247 NILFS_MOUNTED_SNAPSHOTS_RO_ATTR(README);
 248
 249 static struct attribute *nilfs_mounted_snapshots_attrs[] = {
 250         NILFS_MOUNTED_SNAPSHOTS_ATTR_LIST(README),
 251         NULL,
 252 };
 253
 254 NILFS_DEV_INT_GROUP_OPS(mounted_snapshots, dev);
 255 NILFS_DEV_INT_GROUP_TYPE(mounted_snapshots, dev);
 256 NILFS_DEV_INT_GROUP_FNS(mounted_snapshots, dev);
 257
 258 /************************************************************************
 259  *                      NILFS checkpoints attrs                         *
 260  ************************************************************************/
 261
 262 static ssize_t
 263 nilfs_checkpoints_checkpoints_number_show(struct nilfs_checkpoints_attr *attr,
 264                                             struct the_nilfs *nilfs,
 265                                             char *buf)
 266 {
 267         __u64 ncheckpoints;
 268         struct nilfs_cpstat cpstat;
 269         int err;
 270
 271         down_read(&nilfs->ns_segctor_sem);
 272         err = nilfs_cpfile_get_stat(nilfs->ns_cpfile, &cpstat);
 273         up_read(&nilfs->ns_segctor_sem);
 274         if (err < 0) {
 275                 nilfs_msg(nilfs->ns_sb, KERN_ERR,
 276                           "unable to get checkpoint stat: err=%d", err);
 277                 return err;
 278         }
 279
 280         ncheckpoints = cpstat.cs_ncps;
 281
 282         return snprintf(buf, PAGE_SIZE, "%llu\n", ncheckpoints);
 283 }
 284
 285 static ssize_t
 286 nilfs_checkpoints_snapshots_number_show(struct nilfs_checkpoints_attr *attr,
 287                                         struct the_nilfs *nilfs,
 288                                         char *buf)
 289 {
 290         __u64 nsnapshots;
 291         struct nilfs_cpstat cpstat;
 292         int err;
 293
 294         down_read(&nilfs->ns_segctor_sem);
 295         err = nilfs_cpfile_get_stat(nilfs->ns_cpfile, &cpstat);
 296         up_read(&nilfs->ns_segctor_sem);
 297         if (err < 0) {
 298                 nilfs_msg(nilfs->ns_sb, KERN_ERR,
 299                           "unable to get checkpoint stat: err=%d", err);
 300                 return err;
 301         }
 302
 303         nsnapshots = cpstat.cs_nsss;
 304
 305         return snprintf(buf, PAGE_SIZE, "%llu\n", nsnapshots);
 306 }
 307
 308 static ssize_t
 309 nilfs_checkpoints_last_seg_checkpoint_show(struct nilfs_checkpoints_attr *attr,
 310                                             struct the_nilfs *nilfs,
 311                                             char *buf)
 312 {
 313         __u64 last_cno;
 314
 315         spin_lock(&nilfs->ns_last_segment_lock);
 316         last_cno = nilfs->ns_last_cno;
 317         spin_unlock(&nilfs->ns_last_segment_lock);
 318
 319         return snprintf(buf, PAGE_SIZE, "%llu\n", last_cno);
 320 }
 321
 322 static ssize_t
 323 nilfs_checkpoints_next_checkpoint_show(struct nilfs_checkpoints_attr *attr,
 324                                         struct the_nilfs *nilfs,
 325                                         char *buf)
 326 {
 327         __u64 cno;
 328
 329         down_read(&nilfs->ns_segctor_sem);
 330         cno = nilfs->ns_cno;
 331         up_read(&nilfs->ns_segctor_sem);
 332
 333         return snprintf(buf, PAGE_SIZE, "%llu\n", cno);
 334 }
 335
 336 static const char checkpoints_readme_str[] =
 337         "The checkpoints group contains attributes that describe\n"
 338         "details about volume's checkpoints.\n\n"
 339         "(1) checkpoints_number\n\tshow number of checkpoints on volume.\n\n"
 340         "(2) snapshots_number\n\tshow number of snapshots on volume.\n\n"
 341         "(3) last_seg_checkpoint\n"
 342         "\tshow checkpoint number of the latest segment.\n\n"
 343         "(4) next_checkpoint\n\tshow next checkpoint number.\n\n";
 344
 345 static ssize_t
 346 nilfs_checkpoints_README_show(struct nilfs_checkpoints_attr *attr,
 347                                 struct the_nilfs *nilfs, char *buf)
 348 {
 349         return snprintf(buf, PAGE_SIZE, checkpoints_readme_str);
 350 }
 351
 352 NILFS_CHECKPOINTS_RO_ATTR(checkpoints_number);
 353 NILFS_CHECKPOINTS_RO_ATTR(snapshots_number);
 354 NILFS_CHECKPOINTS_RO_ATTR(last_seg_checkpoint);
 355 NILFS_CHECKPOINTS_RO_ATTR(next_checkpoint);
 356 NILFS_CHECKPOINTS_RO_ATTR(README);
 357
 358 static struct attribute *nilfs_checkpoints_attrs[] = {
 359         NILFS_CHECKPOINTS_ATTR_LIST(checkpoints_number),
 360         NILFS_CHECKPOINTS_ATTR_LIST(snapshots_number),
 361         NILFS_CHECKPOINTS_ATTR_LIST(last_seg_checkpoint),
 362         NILFS_CHECKPOINTS_ATTR_LIST(next_checkpoint),
 363         NILFS_CHECKPOINTS_ATTR_LIST(README),
 364         NULL,
 365 };
 366
 367 NILFS_DEV_INT_GROUP_OPS(checkpoints, dev);
 368 NILFS_DEV_INT_GROUP_TYPE(checkpoints, dev);
 369 NILFS_DEV_INT_GROUP_FNS(checkpoints, dev);
 370
 371 /************************************************************************
 372  *                        NILFS segments attrs                          *
 373  ************************************************************************/
 374
 375 static ssize_t
 376 nilfs_segments_segments_number_show(struct nilfs_segments_attr *attr,
 377                                      struct the_nilfs *nilfs,
 378                                      char *buf)
 379 {
 380         return snprintf(buf, PAGE_SIZE, "%lu\n", nilfs->ns_nsegments);
 381 }
 382
 383 static ssize_t
 384 nilfs_segments_blocks_per_segment_show(struct nilfs_segments_attr *attr,
 385                                         struct the_nilfs *nilfs,
 386                                         char *buf)
 387 {
 388         return snprintf(buf, PAGE_SIZE, "%lu\n", nilfs->ns_blocks_per_segment);
 389 }
 390
 391 static ssize_t
 392 nilfs_segments_clean_segments_show(struct nilfs_segments_attr *attr,
 393                                     struct the_nilfs *nilfs,
 394                                     char *buf)
 395 {
 396         unsigned long ncleansegs;
 397
 398         down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
 399         ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile);
 400         up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
 401
 402         return snprintf(buf, PAGE_SIZE, "%lu\n", ncleansegs);
 403 }
 404
 405 static ssize_t
 406 nilfs_segments_dirty_segments_show(struct nilfs_segments_attr *attr,
 407                                     struct the_nilfs *nilfs,
 408                                     char *buf)
 409 {
 410         struct nilfs_sustat sustat;
 411         int err;
 412
 413         down_read(&nilfs->ns_segctor_sem);
 414         err = nilfs_sufile_get_stat(nilfs->ns_sufile, &sustat);
 415         up_read(&nilfs->ns_segctor_sem);
 416         if (err < 0) {
 417                 nilfs_msg(nilfs->ns_sb, KERN_ERR,
 418                           "unable to get segment stat: err=%d", err);
 419                 return err;
 420         }
 421
 422         return snprintf(buf, PAGE_SIZE, "%llu\n", sustat.ss_ndirtysegs);
 423 }
 424
 425 static const char segments_readme_str[] =
 426         "The segments group contains attributes that describe\n"
 427         "details about volume's segments.\n\n"
 428         "(1) segments_number\n\tshow number of segments on volume.\n\n"
 429         "(2) blocks_per_segment\n\tshow number of blocks in segment.\n\n"
 430         "(3) clean_segments\n\tshow count of clean segments.\n\n"
 431         "(4) dirty_segments\n\tshow count of dirty segments.\n\n";
 432
 433 static ssize_t
 434 nilfs_segments_README_show(struct nilfs_segments_attr *attr,
 435                             struct the_nilfs *nilfs,
 436                             char *buf)
 437 {
 438         return snprintf(buf, PAGE_SIZE, segments_readme_str);
 439 }
 440
 441 NILFS_SEGMENTS_RO_ATTR(segments_number);
 442 NILFS_SEGMENTS_RO_ATTR(blocks_per_segment);
 443 NILFS_SEGMENTS_RO_ATTR(clean_segments);
 444 NILFS_SEGMENTS_RO_ATTR(dirty_segments);
 445 NILFS_SEGMENTS_RO_ATTR(README);
 446
 447 static struct attribute *nilfs_segments_attrs[] = {
 448         NILFS_SEGMENTS_ATTR_LIST(segments_number),
 449         NILFS_SEGMENTS_ATTR_LIST(blocks_per_segment),
 450         NILFS_SEGMENTS_ATTR_LIST(clean_segments),
 451         NILFS_SEGMENTS_ATTR_LIST(dirty_segments),
 452         NILFS_SEGMENTS_ATTR_LIST(README),
 453         NULL,
 454 };
 455
 456 NILFS_DEV_INT_GROUP_OPS(segments, dev);
 457 NILFS_DEV_INT_GROUP_TYPE(segments, dev);
 458 NILFS_DEV_INT_GROUP_FNS(segments, dev);
 459
 460 /************************************************************************
 461  *                        NILFS segctor attrs                           *
 462  ************************************************************************/
 463
 464 static ssize_t
 465 nilfs_segctor_last_pseg_block_show(struct nilfs_segctor_attr *attr,
 466                                     struct the_nilfs *nilfs,
 467                                     char *buf)
 468 {
 469         sector_t last_pseg;
 470
 471         spin_lock(&nilfs->ns_last_segment_lock);
 472         last_pseg = nilfs->ns_last_pseg;
 473         spin_unlock(&nilfs->ns_last_segment_lock);
 474
 475         return snprintf(buf, PAGE_SIZE, "%llu\n",
 476                         (unsigned long long)last_pseg);
 477 }
 478
 479 static ssize_t
 480 nilfs_segctor_last_seg_sequence_show(struct nilfs_segctor_attr *attr,
 481                                         struct the_nilfs *nilfs,
 482                                         char *buf)
 483 {
 484         u64 last_seq;
 485
 486         spin_lock(&nilfs->ns_last_segment_lock);
 487         last_seq = nilfs->ns_last_seq;
 488         spin_unlock(&nilfs->ns_last_segment_lock);
 489
 490         return snprintf(buf, PAGE_SIZE, "%llu\n", last_seq);
 491 }
 492
 493 static ssize_t
 494 nilfs_segctor_last_seg_checkpoint_show(struct nilfs_segctor_attr *attr,
 495                                         struct the_nilfs *nilfs,
 496                                         char *buf)
 497 {
 498         __u64 last_cno;
 499
 500         spin_lock(&nilfs->ns_last_segment_lock);
 501         last_cno = nilfs->ns_last_cno;
 502         spin_unlock(&nilfs->ns_last_segment_lock);
 503
 504         return snprintf(buf, PAGE_SIZE, "%llu\n", last_cno);
 505 }
 506
 507 static ssize_t
 508 nilfs_segctor_current_seg_sequence_show(struct nilfs_segctor_attr *attr,
 509                                         struct the_nilfs *nilfs,
 510                                         char *buf)
 511 {
 512         u64 seg_seq;
 513
 514         down_read(&nilfs->ns_segctor_sem);
 515         seg_seq = nilfs->ns_seg_seq;
 516         up_read(&nilfs->ns_segctor_sem);
 517
 518         return snprintf(buf, PAGE_SIZE, "%llu\n", seg_seq);
 519 }
 520
 521 static ssize_t
 522 nilfs_segctor_current_last_full_seg_show(struct nilfs_segctor_attr *attr,
 523                                          struct the_nilfs *nilfs,
 524                                          char *buf)
 525 {
 526         __u64 segnum;
 527
 528         down_read(&nilfs->ns_segctor_sem);
 529         segnum = nilfs->ns_segnum;
 530         up_read(&nilfs->ns_segctor_sem);
 531
 532         return snprintf(buf, PAGE_SIZE, "%llu\n", segnum);
 533 }
 534
 535 static ssize_t
 536 nilfs_segctor_next_full_seg_show(struct nilfs_segctor_attr *attr,
 537                                  struct the_nilfs *nilfs,
 538                                  char *buf)
 539 {
 540         __u64 nextnum;
 541
 542         down_read(&nilfs->ns_segctor_sem);
 543         nextnum = nilfs->ns_nextnum;
 544         up_read(&nilfs->ns_segctor_sem);
 545
 546         return snprintf(buf, PAGE_SIZE, "%llu\n", nextnum);
 547 }
 548
 549 static ssize_t
 550 nilfs_segctor_next_pseg_offset_show(struct nilfs_segctor_attr *attr,
 551                                         struct the_nilfs *nilfs,
 552                                         char *buf)
 553 {
 554         unsigned long pseg_offset;
 555
 556         down_read(&nilfs->ns_segctor_sem);
 557         pseg_offset = nilfs->ns_pseg_offset;
 558         up_read(&nilfs->ns_segctor_sem);
 559
 560         return snprintf(buf, PAGE_SIZE, "%lu\n", pseg_offset);
 561 }
 562
 563 static ssize_t
 564 nilfs_segctor_next_checkpoint_show(struct nilfs_segctor_attr *attr,
 565                                         struct the_nilfs *nilfs,
 566                                         char *buf)
 567 {
 568         __u64 cno;
 569
 570         down_read(&nilfs->ns_segctor_sem);
 571         cno = nilfs->ns_cno;
 572         up_read(&nilfs->ns_segctor_sem);
 573
 574         return snprintf(buf, PAGE_SIZE, "%llu\n", cno);
 575 }
 576
 577 static ssize_t
 578 nilfs_segctor_last_seg_write_time_show(struct nilfs_segctor_attr *attr,
 579                                         struct the_nilfs *nilfs,
 580                                         char *buf)
 581 {
 582         time64_t ctime;
 583
 584         down_read(&nilfs->ns_segctor_sem);
 585         ctime = nilfs->ns_ctime;
 586         up_read(&nilfs->ns_segctor_sem);
 587
 588         return NILFS_SHOW_TIME(ctime, buf);
 589 }
 590
 591 static ssize_t
 592 nilfs_segctor_last_seg_write_time_secs_show(struct nilfs_segctor_attr *attr,
 593                                             struct the_nilfs *nilfs,
 594                                             char *buf)
 595 {
 596         time64_t ctime;
 597
 598         down_read(&nilfs->ns_segctor_sem);
 599         ctime = nilfs->ns_ctime;
 600         up_read(&nilfs->ns_segctor_sem);
 601
 602         return snprintf(buf, PAGE_SIZE, "%llu\n", ctime);
 603 }
 604
 605 static ssize_t
 606 nilfs_segctor_last_nongc_write_time_show(struct nilfs_segctor_attr *attr,
 607                                          struct the_nilfs *nilfs,
 608                                          char *buf)
 609 {
 610         time64_t nongc_ctime;
 611
 612         down_read(&nilfs->ns_segctor_sem);
 613         nongc_ctime = nilfs->ns_nongc_ctime;
 614         up_read(&nilfs->ns_segctor_sem);
 615
 616         return NILFS_SHOW_TIME(nongc_ctime, buf);
 617 }
 618
 619 static ssize_t
 620 nilfs_segctor_last_nongc_write_time_secs_show(struct nilfs_segctor_attr *attr,
 621                                                 struct the_nilfs *nilfs,
 622                                                 char *buf)
 623 {
 624         time64_t nongc_ctime;
 625
 626         down_read(&nilfs->ns_segctor_sem);
 627         nongc_ctime = nilfs->ns_nongc_ctime;
 628         up_read(&nilfs->ns_segctor_sem);
 629
 630         return snprintf(buf, PAGE_SIZE, "%llu\n", nongc_ctime);
 631 }
 632
 633 static ssize_t
 634 nilfs_segctor_dirty_data_blocks_count_show(struct nilfs_segctor_attr *attr,
 635                                             struct the_nilfs *nilfs,
 636                                             char *buf)
 637 {
 638         u32 ndirtyblks;
 639
 640         down_read(&nilfs->ns_segctor_sem);
 641         ndirtyblks = atomic_read(&nilfs->ns_ndirtyblks);
 642         up_read(&nilfs->ns_segctor_sem);
 643
 644         return snprintf(buf, PAGE_SIZE, "%u\n", ndirtyblks);
 645 }
 646
 647 static const char segctor_readme_str[] =
 648         "The segctor group contains attributes that describe\n"
 649         "segctor thread activity details.\n\n"
 650         "(1) last_pseg_block\n"
 651         "\tshow start block number of the latest segment.\n\n"
 652         "(2) last_seg_sequence\n"
 653         "\tshow sequence value of the latest segment.\n\n"
 654         "(3) last_seg_checkpoint\n"
 655         "\tshow checkpoint number of the latest segment.\n\n"
 656         "(4) current_seg_sequence\n\tshow segment sequence counter.\n\n"
 657         "(5) current_last_full_seg\n"
 658         "\tshow index number of the latest full segment.\n\n"
 659         "(6) next_full_seg\n"
 660         "\tshow index number of the full segment index to be used next.\n\n"
 661         "(7) next_pseg_offset\n"
 662         "\tshow offset of next partial segment in the current full segment.\n\n"
 663         "(8) next_checkpoint\n\tshow next checkpoint number.\n\n"
 664         "(9) last_seg_write_time\n"
 665         "\tshow write time of the last segment in human-readable format.\n\n"
 666         "(10) last_seg_write_time_secs\n"
 667         "\tshow write time of the last segment in seconds.\n\n"
 668         "(11) last_nongc_write_time\n"
 669         "\tshow write time of the last segment not for cleaner operation "
 670         "in human-readable format.\n\n"
 671         "(12) last_nongc_write_time_secs\n"
 672         "\tshow write time of the last segment not for cleaner operation "
 673         "in seconds.\n\n"
 674         "(13) dirty_data_blocks_count\n"
 675         "\tshow number of dirty data blocks.\n\n";
 676
 677 static ssize_t
 678 nilfs_segctor_README_show(struct nilfs_segctor_attr *attr,
 679                           struct the_nilfs *nilfs, char *buf)
 680 {
 681         return snprintf(buf, PAGE_SIZE, segctor_readme_str);
 682 }
 683
 684 NILFS_SEGCTOR_RO_ATTR(last_pseg_block);
 685 NILFS_SEGCTOR_RO_ATTR(last_seg_sequence);
 686 NILFS_SEGCTOR_RO_ATTR(last_seg_checkpoint);
 687 NILFS_SEGCTOR_RO_ATTR(current_seg_sequence);
 688 NILFS_SEGCTOR_RO_ATTR(current_last_full_seg);
 689 NILFS_SEGCTOR_RO_ATTR(next_full_seg);
 690 NILFS_SEGCTOR_RO_ATTR(next_pseg_offset);
 691 NILFS_SEGCTOR_RO_ATTR(next_checkpoint);
 692 NILFS_SEGCTOR_RO_ATTR(last_seg_write_time);
 693 NILFS_SEGCTOR_RO_ATTR(last_seg_write_time_secs);
 694 NILFS_SEGCTOR_RO_ATTR(last_nongc_write_time);
 695 NILFS_SEGCTOR_RO_ATTR(last_nongc_write_time_secs);
 696 NILFS_SEGCTOR_RO_ATTR(dirty_data_blocks_count);
 697 NILFS_SEGCTOR_RO_ATTR(README);
 698
 699 static struct attribute *nilfs_segctor_attrs[] = {
 700         NILFS_SEGCTOR_ATTR_LIST(last_pseg_block),
 701         NILFS_SEGCTOR_ATTR_LIST(last_seg_sequence),
 702         NILFS_SEGCTOR_ATTR_LIST(last_seg_checkpoint),
 703         NILFS_SEGCTOR_ATTR_LIST(current_seg_sequence),
 704         NILFS_SEGCTOR_ATTR_LIST(current_last_full_seg),
 705         NILFS_SEGCTOR_ATTR_LIST(next_full_seg),
 706         NILFS_SEGCTOR_ATTR_LIST(next_pseg_offset),
 707         NILFS_SEGCTOR_ATTR_LIST(next_checkpoint),
 708         NILFS_SEGCTOR_ATTR_LIST(last_seg_write_time),
 709         NILFS_SEGCTOR_ATTR_LIST(last_seg_write_time_secs),
 710         NILFS_SEGCTOR_ATTR_LIST(last_nongc_write_time),
 711         NILFS_SEGCTOR_ATTR_LIST(last_nongc_write_time_secs),
 712         NILFS_SEGCTOR_ATTR_LIST(dirty_data_blocks_count),
 713         NILFS_SEGCTOR_ATTR_LIST(README),
 714         NULL,
 715 };
 716
 717 NILFS_DEV_INT_GROUP_OPS(segctor, dev);
 718 NILFS_DEV_INT_GROUP_TYPE(segctor, dev);
 719 NILFS_DEV_INT_GROUP_FNS(segctor, dev);
 720
 721 /************************************************************************
 722  *                        NILFS superblock attrs                        *
 723  ************************************************************************/
 724
 725 static ssize_t
 726 nilfs_superblock_sb_write_time_show(struct nilfs_superblock_attr *attr,
 727                                      struct the_nilfs *nilfs,
 728                                      char *buf)
 729 {
 730         time64_t sbwtime;
 731
 732         down_read(&nilfs->ns_sem);
 733         sbwtime = nilfs->ns_sbwtime;
 734         up_read(&nilfs->ns_sem);
 735
 736         return NILFS_SHOW_TIME(sbwtime, buf);
 737 }
 738
 739 static ssize_t
 740 nilfs_superblock_sb_write_time_secs_show(struct nilfs_superblock_attr *attr,
 741                                          struct the_nilfs *nilfs,
 742                                          char *buf)
 743 {
 744         time64_t sbwtime;
 745
 746         down_read(&nilfs->ns_sem);
 747         sbwtime = nilfs->ns_sbwtime;
 748         up_read(&nilfs->ns_sem);
 749
 750         return snprintf(buf, PAGE_SIZE, "%llu\n", sbwtime);
 751 }
 752
 753 static ssize_t
 754 nilfs_superblock_sb_write_count_show(struct nilfs_superblock_attr *attr,
 755                                       struct the_nilfs *nilfs,
 756                                       char *buf)
 757 {
 758         unsigned int sbwcount;
 759
 760         down_read(&nilfs->ns_sem);
 761         sbwcount = nilfs->ns_sbwcount;
 762         up_read(&nilfs->ns_sem);
 763
 764         return snprintf(buf, PAGE_SIZE, "%u\n", sbwcount);
 765 }
 766
 767 static ssize_t
 768 nilfs_superblock_sb_update_frequency_show(struct nilfs_superblock_attr *attr,
 769                                             struct the_nilfs *nilfs,
 770                                             char *buf)
 771 {
 772         unsigned int sb_update_freq;
 773
 774         down_read(&nilfs->ns_sem);
 775         sb_update_freq = nilfs->ns_sb_update_freq;
 776         up_read(&nilfs->ns_sem);
 777
 778         return snprintf(buf, PAGE_SIZE, "%u\n", sb_update_freq);
 779 }
 780
 781 static ssize_t
 782 nilfs_superblock_sb_update_frequency_store(struct nilfs_superblock_attr *attr,
 783                                             struct the_nilfs *nilfs,
 784                                             const char *buf, size_t count)
 785 {
 786         unsigned int val;
 787         int err;
 788
 789         err = kstrtouint(skip_spaces(buf), 0, &val);
 790         if (err) {
 791                 nilfs_msg(nilfs->ns_sb, KERN_ERR,
 792                           "unable to convert string: err=%d", err);
 793                 return err;
 794         }
 795
 796         if (val < NILFS_SB_FREQ) {
 797                 val = NILFS_SB_FREQ;
 798                 nilfs_msg(nilfs->ns_sb, KERN_WARNING,
 799                           "superblock update frequency cannot be lesser than 10 seconds");
 800         }
 801
 802         down_write(&nilfs->ns_sem);
 803         nilfs->ns_sb_update_freq = val;
 804         up_write(&nilfs->ns_sem);
 805
 806         return count;
 807 }
 808
 809 static const char sb_readme_str[] =
 810         "The superblock group contains attributes that describe\n"
 811         "superblock's details.\n\n"
 812         "(1) sb_write_time\n\tshow previous write time of super block "
 813         "in human-readable format.\n\n"
 814         "(2) sb_write_time_secs\n\tshow previous write time of super block "
 815         "in seconds.\n\n"
 816         "(3) sb_write_count\n\tshow write count of super block.\n\n"
 817         "(4) sb_update_frequency\n"
 818         "\tshow/set interval of periodical update of superblock (in seconds).\n\n"
 819         "\tYou can set preferable frequency of superblock update by command:\n\n"
 820         "\t'echo <val> > /sys/fs/<nilfs>/<dev>/superblock/sb_update_frequency'\n";
 821
 822 static ssize_t
 823 nilfs_superblock_README_show(struct nilfs_superblock_attr *attr,
 824                                 struct the_nilfs *nilfs, char *buf)
 825 {
 826         return snprintf(buf, PAGE_SIZE, sb_readme_str);
 827 }
 828
 829 NILFS_SUPERBLOCK_RO_ATTR(sb_write_time);
 830 NILFS_SUPERBLOCK_RO_ATTR(sb_write_time_secs);
 831 NILFS_SUPERBLOCK_RO_ATTR(sb_write_count);
 832 NILFS_SUPERBLOCK_RW_ATTR(sb_update_frequency);
 833 NILFS_SUPERBLOCK_RO_ATTR(README);
 834
 835 static struct attribute *nilfs_superblock_attrs[] = {
 836         NILFS_SUPERBLOCK_ATTR_LIST(sb_write_time),
 837         NILFS_SUPERBLOCK_ATTR_LIST(sb_write_time_secs),
 838         NILFS_SUPERBLOCK_ATTR_LIST(sb_write_count),
 839         NILFS_SUPERBLOCK_ATTR_LIST(sb_update_frequency),
 840         NILFS_SUPERBLOCK_ATTR_LIST(README),
 841         NULL,
 842 };
 843
 844 NILFS_DEV_INT_GROUP_OPS(superblock, dev);
 845 NILFS_DEV_INT_GROUP_TYPE(superblock, dev);
 846 NILFS_DEV_INT_GROUP_FNS(superblock, dev);
 847
 848 /************************************************************************
 849  *                        NILFS device attrs                            *
 850  ************************************************************************/
 851
 852 static
 853 ssize_t nilfs_dev_revision_show(struct nilfs_dev_attr *attr,
 854                                 struct the_nilfs *nilfs,
 855                                 char *buf)
 856 {
 857         struct nilfs_super_block **sbp = nilfs->ns_sbp;
 858         u32 major = le32_to_cpu(sbp[0]->s_rev_level);
 859         u16 minor = le16_to_cpu(sbp[0]->s_minor_rev_level);
 860
 861         return snprintf(buf, PAGE_SIZE, "%d.%d\n", major, minor);
 862 }
 863
 864 static
 865 ssize_t nilfs_dev_blocksize_show(struct nilfs_dev_attr *attr,
 866                                  struct the_nilfs *nilfs,
 867                                  char *buf)
 868 {
 869         return snprintf(buf, PAGE_SIZE, "%u\n", nilfs->ns_blocksize);
 870 }
 871
 872 static
 873 ssize_t nilfs_dev_device_size_show(struct nilfs_dev_attr *attr,
 874                                     struct the_nilfs *nilfs,
 875                                     char *buf)
 876 {
 877         struct nilfs_super_block **sbp = nilfs->ns_sbp;
 878         u64 dev_size = le64_to_cpu(sbp[0]->s_dev_size);
 879
 880         return snprintf(buf, PAGE_SIZE, "%llu\n", dev_size);
 881 }
 882
 883 static
 884 ssize_t nilfs_dev_free_blocks_show(struct nilfs_dev_attr *attr,
 885                                    struct the_nilfs *nilfs,
 886                                    char *buf)
 887 {
 888         sector_t free_blocks = 0;
 889
 890         nilfs_count_free_blocks(nilfs, &free_blocks);
 891         return snprintf(buf, PAGE_SIZE, "%llu\n",
 892                         (unsigned long long)free_blocks);
 893 }
 894
 895 static
 896 ssize_t nilfs_dev_uuid_show(struct nilfs_dev_attr *attr,
 897                             struct the_nilfs *nilfs,
 898                             char *buf)
 899 {
 900         struct nilfs_super_block **sbp = nilfs->ns_sbp;
 901
 902         return snprintf(buf, PAGE_SIZE, "%pUb\n", sbp[0]->s_uuid);
 903 }
 904
 905 static
 906 ssize_t nilfs_dev_volume_name_show(struct nilfs_dev_attr *attr,
 907                                     struct the_nilfs *nilfs,
 908                                     char *buf)
 909 {
 910         struct nilfs_super_block **sbp = nilfs->ns_sbp;
 911
 912         return scnprintf(buf, sizeof(sbp[0]->s_volume_name), "%s\n",
 913                          sbp[0]->s_volume_name);
 914 }
 915
 916 static const char dev_readme_str[] =
 917         "The <device> group contains attributes that describe file system\n"
 918         "partition's details.\n\n"
 919         "(1) revision\n\tshow NILFS file system revision.\n\n"
 920         "(2) blocksize\n\tshow volume block size in bytes.\n\n"
 921         "(3) device_size\n\tshow volume size in bytes.\n\n"
 922         "(4) free_blocks\n\tshow count of free blocks on volume.\n\n"
 923         "(5) uuid\n\tshow volume's UUID.\n\n"
 924         "(6) volume_name\n\tshow volume's name.\n\n";
 925
 926 static ssize_t nilfs_dev_README_show(struct nilfs_dev_attr *attr,
 927                                      struct the_nilfs *nilfs,
 928                                      char *buf)
 929 {
 930         return snprintf(buf, PAGE_SIZE, dev_readme_str);
 931 }
 932
 933 NILFS_DEV_RO_ATTR(revision);
 934 NILFS_DEV_RO_ATTR(blocksize);
 935 NILFS_DEV_RO_ATTR(device_size);
 936 NILFS_DEV_RO_ATTR(free_blocks);
 937 NILFS_DEV_RO_ATTR(uuid);
 938 NILFS_DEV_RO_ATTR(volume_name);
 939 NILFS_DEV_RO_ATTR(README);
 940
 941 static struct attribute *nilfs_dev_attrs[] = {
 942         NILFS_DEV_ATTR_LIST(revision),
 943         NILFS_DEV_ATTR_LIST(blocksize),
 944         NILFS_DEV_ATTR_LIST(device_size),
 945         NILFS_DEV_ATTR_LIST(free_blocks),
 946         NILFS_DEV_ATTR_LIST(uuid),
 947         NILFS_DEV_ATTR_LIST(volume_name),
 948         NILFS_DEV_ATTR_LIST(README),
 949         NULL,
 950 };
 951
 952 static ssize_t nilfs_dev_attr_show(struct kobject *kobj,
 953                                     struct attribute *attr, char *buf)
 954 {
 955         struct the_nilfs *nilfs = container_of(kobj, struct the_nilfs,
 956                                                 ns_dev_kobj);
 957         struct nilfs_dev_attr *a = container_of(attr, struct nilfs_dev_attr,
 958                                                 attr);
 959
 960         return a->show ? a->show(a, nilfs, buf) : 0;
 961 }
 962
 963 static ssize_t nilfs_dev_attr_store(struct kobject *kobj,
 964                                     struct attribute *attr,
 965                                     const char *buf, size_t len)
 966 {
 967         struct the_nilfs *nilfs = container_of(kobj, struct the_nilfs,
 968                                                 ns_dev_kobj);
 969         struct nilfs_dev_attr *a = container_of(attr, struct nilfs_dev_attr,
 970                                                 attr);
 971
 972         return a->store ? a->store(a, nilfs, buf, len) : 0;
 973 }
 974
 975 static void nilfs_dev_attr_release(struct kobject *kobj)
 976 {
 977         struct the_nilfs *nilfs = container_of(kobj, struct the_nilfs,
 978                                                 ns_dev_kobj);
 979         complete(&nilfs->ns_dev_kobj_unregister);
 980 }
 981
 982 static const struct sysfs_ops nilfs_dev_attr_ops = {
 983         .show   = nilfs_dev_attr_show,
 984         .store  = nilfs_dev_attr_store,
 985 };
 986
 987 static struct kobj_type nilfs_dev_ktype = {
 988         .default_attrs  = nilfs_dev_attrs,
 989         .sysfs_ops      = &nilfs_dev_attr_ops,
 990         .release        = nilfs_dev_attr_release,
 991 };
 992
 993 int nilfs_sysfs_create_device_group(struct super_block *sb)
 994 {
 995         struct the_nilfs *nilfs = sb->s_fs_info;
 996         size_t devgrp_size = sizeof(struct nilfs_sysfs_dev_subgroups);
 997         int err;
 998
 999         nilfs->ns_dev_subgroups = kzalloc(devgrp_size, GFP_KERNEL);
1000         if (unlikely(!nilfs->ns_dev_subgroups)) {
1001                 err = -ENOMEM;
1002                 nilfs_msg(sb, KERN_ERR,
1003                           "unable to allocate memory for device group");
1004                 goto failed_create_device_group;
1005         }
1006
1007         nilfs->ns_dev_kobj.kset = nilfs_kset;
1008         init_completion(&nilfs->ns_dev_kobj_unregister);
1009         err = kobject_init_and_add(&nilfs->ns_dev_kobj, &nilfs_dev_ktype, NULL,
1010                                     "%s", sb->s_id);
1011         if (err)
1012                 goto free_dev_subgroups;
1013
1014         err = nilfs_sysfs_create_mounted_snapshots_group(nilfs);
1015         if (err)
1016                 goto cleanup_dev_kobject;
1017
1018         err = nilfs_sysfs_create_checkpoints_group(nilfs);
1019         if (err)
1020                 goto delete_mounted_snapshots_group;
1021
1022         err = nilfs_sysfs_create_segments_group(nilfs);
1023         if (err)
1024                 goto delete_checkpoints_group;
1025
1026         err = nilfs_sysfs_create_superblock_group(nilfs);
1027         if (err)
1028                 goto delete_segments_group;
1029
1030         err = nilfs_sysfs_create_segctor_group(nilfs);
1031         if (err)
1032                 goto delete_superblock_group;
1033
1034         return 0;
1035
1036 delete_superblock_group:
1037         nilfs_sysfs_delete_superblock_group(nilfs);
1038
1039 delete_segments_group:
1040         nilfs_sysfs_delete_segments_group(nilfs);
1041
1042 delete_checkpoints_group:
1043         nilfs_sysfs_delete_checkpoints_group(nilfs);
1044
1045 delete_mounted_snapshots_group:
1046         nilfs_sysfs_delete_mounted_snapshots_group(nilfs);
1047
1048 cleanup_dev_kobject:
1049         kobject_del(&nilfs->ns_dev_kobj);
1050
1051 free_dev_subgroups:
1052         kfree(nilfs->ns_dev_subgroups);
1053
1054 failed_create_device_group:
1055         return err;
1056 }
1057
1058 void nilfs_sysfs_delete_device_group(struct the_nilfs *nilfs)
1059 {
1060         nilfs_sysfs_delete_mounted_snapshots_group(nilfs);
1061         nilfs_sysfs_delete_checkpoints_group(nilfs);
1062         nilfs_sysfs_delete_segments_group(nilfs);
1063         nilfs_sysfs_delete_superblock_group(nilfs);
1064         nilfs_sysfs_delete_segctor_group(nilfs);
1065         kobject_del(&nilfs->ns_dev_kobj);
1066         kfree(nilfs->ns_dev_subgroups);
1067 }
1068
1069 /************************************************************************
1070  *                        NILFS feature attrs                           *
1071  ************************************************************************/
1072
1073 static ssize_t nilfs_feature_revision_show(struct kobject *kobj,
1074                                             struct attribute *attr, char *buf)
1075 {
1076         return snprintf(buf, PAGE_SIZE, "%d.%d\n",
1077                         NILFS_CURRENT_REV, NILFS_MINOR_REV);
1078 }
1079
1080 static const char features_readme_str[] =
1081         "The features group contains attributes that describe NILFS file\n"
1082         "system driver features.\n\n"
1083         "(1) revision\n\tshow current revision of NILFS file system driver.\n";
1084
1085 static ssize_t nilfs_feature_README_show(struct kobject *kobj,
1086                                          struct attribute *attr,
1087                                          char *buf)
1088 {
1089         return snprintf(buf, PAGE_SIZE, features_readme_str);
1090 }
1091
1092 NILFS_FEATURE_RO_ATTR(revision);
1093 NILFS_FEATURE_RO_ATTR(README);
1094
1095 static struct attribute *nilfs_feature_attrs[] = {
1096         NILFS_FEATURE_ATTR_LIST(revision),
1097         NILFS_FEATURE_ATTR_LIST(README),
1098         NULL,
1099 };
1100
1101 static const struct attribute_group nilfs_feature_attr_group = {
1102         .name = "features",
1103         .attrs = nilfs_feature_attrs,
1104 };
1105
1106 int __init nilfs_sysfs_init(void)
1107 {
1108         int err;
1109
1110         nilfs_kset = kset_create_and_add(NILFS_ROOT_GROUP_NAME, NULL, fs_kobj);
1111         if (!nilfs_kset) {
1112                 err = -ENOMEM;
1113                 nilfs_msg(NULL, KERN_ERR,
1114                           "unable to create sysfs entry: err=%d", err);
1115                 goto failed_sysfs_init;
1116         }
1117
1118         err = sysfs_create_group(&nilfs_kset->kobj, &nilfs_feature_attr_group);
1119         if (unlikely(err)) {
1120                 nilfs_msg(NULL, KERN_ERR,
1121                           "unable to create feature group: err=%d", err);
1122                 goto cleanup_sysfs_init;
1123         }
1124
1125         return 0;
1126
1127 cleanup_sysfs_init:
1128         kset_unregister(nilfs_kset);
1129
1130 failed_sysfs_init:
1131         return err;
1132 }
1133
1134 void nilfs_sysfs_exit(void)
1135 {
1136         sysfs_remove_group(&nilfs_kset->kobj, &nilfs_feature_attr_group);
1137         kset_unregister(nilfs_kset);
1138 }