e2b8b3437c589734553eb6abf73066b7cc8f347d
[releases.git] / sysfs.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  linux/fs/ext4/sysfs.c
4  *
5  * Copyright (C) 1992, 1993, 1994, 1995
6  * Remy Card (card@masi.ibp.fr)
7  * Theodore Ts'o (tytso@mit.edu)
8  *
9  */
10
11 #include <linux/time.h>
12 #include <linux/fs.h>
13 #include <linux/seq_file.h>
14 #include <linux/slab.h>
15 #include <linux/proc_fs.h>
16 #include <linux/part_stat.h>
17
18 #include "ext4.h"
19 #include "ext4_jbd2.h"
20
21 typedef enum {
22         attr_noop,
23         attr_delayed_allocation_blocks,
24         attr_session_write_kbytes,
25         attr_lifetime_write_kbytes,
26         attr_reserved_clusters,
27         attr_sra_exceeded_retry_limit,
28         attr_inode_readahead,
29         attr_trigger_test_error,
30         attr_first_error_time,
31         attr_last_error_time,
32         attr_feature,
33         attr_pointer_ui,
34         attr_pointer_ul,
35         attr_pointer_u64,
36         attr_pointer_u8,
37         attr_pointer_string,
38         attr_pointer_atomic,
39         attr_journal_task,
40 } attr_id_t;
41
42 typedef enum {
43         ptr_explicit,
44         ptr_ext4_sb_info_offset,
45         ptr_ext4_super_block_offset,
46 } attr_ptr_t;
47
48 static const char proc_dirname[] = "fs/ext4";
49 static struct proc_dir_entry *ext4_proc_root;
50
51 struct ext4_attr {
52         struct attribute attr;
53         short attr_id;
54         short attr_ptr;
55         unsigned short attr_size;
56         union {
57                 int offset;
58                 void *explicit_ptr;
59         } u;
60 };
61
62 static ssize_t session_write_kbytes_show(struct ext4_sb_info *sbi, char *buf)
63 {
64         struct super_block *sb = sbi->s_buddy_cache->i_sb;
65
66         return sysfs_emit(buf, "%lu\n",
67                         (part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
68                          sbi->s_sectors_written_start) >> 1);
69 }
70
71 static ssize_t lifetime_write_kbytes_show(struct ext4_sb_info *sbi, char *buf)
72 {
73         struct super_block *sb = sbi->s_buddy_cache->i_sb;
74
75         return sysfs_emit(buf, "%llu\n",
76                         (unsigned long long)(sbi->s_kbytes_written +
77                         ((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
78                           EXT4_SB(sb)->s_sectors_written_start) >> 1)));
79 }
80
81 static ssize_t inode_readahead_blks_store(struct ext4_sb_info *sbi,
82                                           const char *buf, size_t count)
83 {
84         unsigned long t;
85         int ret;
86
87         ret = kstrtoul(skip_spaces(buf), 0, &t);
88         if (ret)
89                 return ret;
90
91         if (t && (!is_power_of_2(t) || t > 0x40000000))
92                 return -EINVAL;
93
94         sbi->s_inode_readahead_blks = t;
95         return count;
96 }
97
98 static ssize_t reserved_clusters_store(struct ext4_sb_info *sbi,
99                                    const char *buf, size_t count)
100 {
101         unsigned long long val;
102         ext4_fsblk_t clusters = (ext4_blocks_count(sbi->s_es) >>
103                                  sbi->s_cluster_bits);
104         int ret;
105
106         ret = kstrtoull(skip_spaces(buf), 0, &val);
107         if (ret || val >= clusters)
108                 return -EINVAL;
109
110         atomic64_set(&sbi->s_resv_clusters, val);
111         return count;
112 }
113
114 static ssize_t trigger_test_error(struct ext4_sb_info *sbi,
115                                   const char *buf, size_t count)
116 {
117         int len = count;
118
119         if (!capable(CAP_SYS_ADMIN))
120                 return -EPERM;
121
122         if (len && buf[len-1] == '\n')
123                 len--;
124
125         if (len)
126                 ext4_error(sbi->s_sb, "%.*s", len, buf);
127         return count;
128 }
129
130 static ssize_t journal_task_show(struct ext4_sb_info *sbi, char *buf)
131 {
132         if (!sbi->s_journal)
133                 return sysfs_emit(buf, "<none>\n");
134         return sysfs_emit(buf, "%d\n",
135                         task_pid_vnr(sbi->s_journal->j_task));
136 }
137
138 #define EXT4_ATTR(_name,_mode,_id)                                      \
139 static struct ext4_attr ext4_attr_##_name = {                           \
140         .attr = {.name = __stringify(_name), .mode = _mode },           \
141         .attr_id = attr_##_id,                                          \
142 }
143
144 #define EXT4_ATTR_FUNC(_name,_mode)  EXT4_ATTR(_name,_mode,_name)
145
146 #define EXT4_ATTR_FEATURE(_name)   EXT4_ATTR(_name, 0444, feature)
147
148 #define EXT4_ATTR_OFFSET(_name,_mode,_id,_struct,_elname)       \
149 static struct ext4_attr ext4_attr_##_name = {                   \
150         .attr = {.name = __stringify(_name), .mode = _mode },   \
151         .attr_id = attr_##_id,                                  \
152         .attr_ptr = ptr_##_struct##_offset,                     \
153         .u = {                                                  \
154                 .offset = offsetof(struct _struct, _elname),\
155         },                                                      \
156 }
157
158 #define EXT4_ATTR_STRING(_name,_mode,_size,_struct,_elname)     \
159 static struct ext4_attr ext4_attr_##_name = {                   \
160         .attr = {.name = __stringify(_name), .mode = _mode },   \
161         .attr_id = attr_pointer_string,                         \
162         .attr_size = _size,                                     \
163         .attr_ptr = ptr_##_struct##_offset,                     \
164         .u = {                                                  \
165                 .offset = offsetof(struct _struct, _elname),\
166         },                                                      \
167 }
168
169 #define EXT4_RO_ATTR_ES_UI(_name,_elname)                               \
170         EXT4_ATTR_OFFSET(_name, 0444, pointer_ui, ext4_super_block, _elname)
171
172 #define EXT4_RO_ATTR_ES_U8(_name,_elname)                               \
173         EXT4_ATTR_OFFSET(_name, 0444, pointer_u8, ext4_super_block, _elname)
174
175 #define EXT4_RO_ATTR_ES_U64(_name,_elname)                              \
176         EXT4_ATTR_OFFSET(_name, 0444, pointer_u64, ext4_super_block, _elname)
177
178 #define EXT4_RO_ATTR_ES_STRING(_name,_elname,_size)                     \
179         EXT4_ATTR_STRING(_name, 0444, _size, ext4_super_block, _elname)
180
181 #define EXT4_RW_ATTR_SBI_UI(_name,_elname)      \
182         EXT4_ATTR_OFFSET(_name, 0644, pointer_ui, ext4_sb_info, _elname)
183
184 #define EXT4_RW_ATTR_SBI_UL(_name,_elname)      \
185         EXT4_ATTR_OFFSET(_name, 0644, pointer_ul, ext4_sb_info, _elname)
186
187 #define EXT4_RO_ATTR_SBI_ATOMIC(_name,_elname)  \
188         EXT4_ATTR_OFFSET(_name, 0444, pointer_atomic, ext4_sb_info, _elname)
189
190 #define EXT4_ATTR_PTR(_name,_mode,_id,_ptr) \
191 static struct ext4_attr ext4_attr_##_name = {                   \
192         .attr = {.name = __stringify(_name), .mode = _mode },   \
193         .attr_id = attr_##_id,                                  \
194         .attr_ptr = ptr_explicit,                               \
195         .u = {                                                  \
196                 .explicit_ptr = _ptr,                           \
197         },                                                      \
198 }
199
200 #define ATTR_LIST(name) &ext4_attr_##name.attr
201
202 EXT4_ATTR_FUNC(delayed_allocation_blocks, 0444);
203 EXT4_ATTR_FUNC(session_write_kbytes, 0444);
204 EXT4_ATTR_FUNC(lifetime_write_kbytes, 0444);
205 EXT4_ATTR_FUNC(reserved_clusters, 0644);
206 EXT4_ATTR_FUNC(sra_exceeded_retry_limit, 0444);
207
208 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, inode_readahead,
209                  ext4_sb_info, s_inode_readahead_blks);
210 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
211 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
212 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
213 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
214 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
215 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
216 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
217 EXT4_RW_ATTR_SBI_UI(mb_max_inode_prealloc, s_mb_max_inode_prealloc);
218 EXT4_RW_ATTR_SBI_UI(mb_max_linear_groups, s_mb_max_linear_groups);
219 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
220 EXT4_ATTR(trigger_fs_error, 0200, trigger_test_error);
221 EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);
222 EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst);
223 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);
224 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst);
225 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval);
226 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst);
227 #ifdef CONFIG_EXT4_DEBUG
228 EXT4_RW_ATTR_SBI_UL(simulate_fail, s_simulate_fail);
229 #endif
230 EXT4_RO_ATTR_SBI_ATOMIC(warning_count, s_warning_count);
231 EXT4_RO_ATTR_SBI_ATOMIC(msg_count, s_msg_count);
232 EXT4_RO_ATTR_ES_UI(errors_count, s_error_count);
233 EXT4_RO_ATTR_ES_U8(first_error_errcode, s_first_error_errcode);
234 EXT4_RO_ATTR_ES_U8(last_error_errcode, s_last_error_errcode);
235 EXT4_RO_ATTR_ES_UI(first_error_ino, s_first_error_ino);
236 EXT4_RO_ATTR_ES_UI(last_error_ino, s_last_error_ino);
237 EXT4_RO_ATTR_ES_U64(first_error_block, s_first_error_block);
238 EXT4_RO_ATTR_ES_U64(last_error_block, s_last_error_block);
239 EXT4_RO_ATTR_ES_UI(first_error_line, s_first_error_line);
240 EXT4_RO_ATTR_ES_UI(last_error_line, s_last_error_line);
241 EXT4_RO_ATTR_ES_STRING(first_error_func, s_first_error_func, 32);
242 EXT4_RO_ATTR_ES_STRING(last_error_func, s_last_error_func, 32);
243 EXT4_ATTR(first_error_time, 0444, first_error_time);
244 EXT4_ATTR(last_error_time, 0444, last_error_time);
245 EXT4_ATTR(journal_task, 0444, journal_task);
246 EXT4_RW_ATTR_SBI_UI(mb_prefetch, s_mb_prefetch);
247 EXT4_RW_ATTR_SBI_UI(mb_prefetch_limit, s_mb_prefetch_limit);
248 EXT4_RW_ATTR_SBI_UL(last_trim_minblks, s_last_trim_minblks);
249
250 static unsigned int old_bump_val = 128;
251 EXT4_ATTR_PTR(max_writeback_mb_bump, 0444, pointer_ui, &old_bump_val);
252
253 static struct attribute *ext4_attrs[] = {
254         ATTR_LIST(delayed_allocation_blocks),
255         ATTR_LIST(session_write_kbytes),
256         ATTR_LIST(lifetime_write_kbytes),
257         ATTR_LIST(reserved_clusters),
258         ATTR_LIST(sra_exceeded_retry_limit),
259         ATTR_LIST(inode_readahead_blks),
260         ATTR_LIST(inode_goal),
261         ATTR_LIST(mb_stats),
262         ATTR_LIST(mb_max_to_scan),
263         ATTR_LIST(mb_min_to_scan),
264         ATTR_LIST(mb_order2_req),
265         ATTR_LIST(mb_stream_req),
266         ATTR_LIST(mb_group_prealloc),
267         ATTR_LIST(mb_max_inode_prealloc),
268         ATTR_LIST(mb_max_linear_groups),
269         ATTR_LIST(max_writeback_mb_bump),
270         ATTR_LIST(extent_max_zeroout_kb),
271         ATTR_LIST(trigger_fs_error),
272         ATTR_LIST(err_ratelimit_interval_ms),
273         ATTR_LIST(err_ratelimit_burst),
274         ATTR_LIST(warning_ratelimit_interval_ms),
275         ATTR_LIST(warning_ratelimit_burst),
276         ATTR_LIST(msg_ratelimit_interval_ms),
277         ATTR_LIST(msg_ratelimit_burst),
278         ATTR_LIST(errors_count),
279         ATTR_LIST(warning_count),
280         ATTR_LIST(msg_count),
281         ATTR_LIST(first_error_ino),
282         ATTR_LIST(last_error_ino),
283         ATTR_LIST(first_error_block),
284         ATTR_LIST(last_error_block),
285         ATTR_LIST(first_error_line),
286         ATTR_LIST(last_error_line),
287         ATTR_LIST(first_error_func),
288         ATTR_LIST(last_error_func),
289         ATTR_LIST(first_error_errcode),
290         ATTR_LIST(last_error_errcode),
291         ATTR_LIST(first_error_time),
292         ATTR_LIST(last_error_time),
293         ATTR_LIST(journal_task),
294 #ifdef CONFIG_EXT4_DEBUG
295         ATTR_LIST(simulate_fail),
296 #endif
297         ATTR_LIST(mb_prefetch),
298         ATTR_LIST(mb_prefetch_limit),
299         ATTR_LIST(last_trim_minblks),
300         NULL,
301 };
302 ATTRIBUTE_GROUPS(ext4);
303
304 /* Features this copy of ext4 supports */
305 EXT4_ATTR_FEATURE(lazy_itable_init);
306 EXT4_ATTR_FEATURE(batched_discard);
307 EXT4_ATTR_FEATURE(meta_bg_resize);
308 #ifdef CONFIG_FS_ENCRYPTION
309 EXT4_ATTR_FEATURE(encryption);
310 EXT4_ATTR_FEATURE(test_dummy_encryption_v2);
311 #endif
312 #if IS_ENABLED(CONFIG_UNICODE)
313 EXT4_ATTR_FEATURE(casefold);
314 #endif
315 #ifdef CONFIG_FS_VERITY
316 EXT4_ATTR_FEATURE(verity);
317 #endif
318 EXT4_ATTR_FEATURE(metadata_csum_seed);
319 EXT4_ATTR_FEATURE(fast_commit);
320 #if IS_ENABLED(CONFIG_UNICODE) && defined(CONFIG_FS_ENCRYPTION)
321 EXT4_ATTR_FEATURE(encrypted_casefold);
322 #endif
323
324 static struct attribute *ext4_feat_attrs[] = {
325         ATTR_LIST(lazy_itable_init),
326         ATTR_LIST(batched_discard),
327         ATTR_LIST(meta_bg_resize),
328 #ifdef CONFIG_FS_ENCRYPTION
329         ATTR_LIST(encryption),
330         ATTR_LIST(test_dummy_encryption_v2),
331 #endif
332 #if IS_ENABLED(CONFIG_UNICODE)
333         ATTR_LIST(casefold),
334 #endif
335 #ifdef CONFIG_FS_VERITY
336         ATTR_LIST(verity),
337 #endif
338         ATTR_LIST(metadata_csum_seed),
339         ATTR_LIST(fast_commit),
340 #if IS_ENABLED(CONFIG_UNICODE) && defined(CONFIG_FS_ENCRYPTION)
341         ATTR_LIST(encrypted_casefold),
342 #endif
343         NULL,
344 };
345 ATTRIBUTE_GROUPS(ext4_feat);
346
347 static void *calc_ptr(struct ext4_attr *a, struct ext4_sb_info *sbi)
348 {
349         switch (a->attr_ptr) {
350         case ptr_explicit:
351                 return a->u.explicit_ptr;
352         case ptr_ext4_sb_info_offset:
353                 return (void *) (((char *) sbi) + a->u.offset);
354         case ptr_ext4_super_block_offset:
355                 return (void *) (((char *) sbi->s_es) + a->u.offset);
356         }
357         return NULL;
358 }
359
360 static ssize_t __print_tstamp(char *buf, __le32 lo, __u8 hi)
361 {
362         return sysfs_emit(buf, "%lld\n",
363                         ((time64_t)hi << 32) + le32_to_cpu(lo));
364 }
365
366 #define print_tstamp(buf, es, tstamp) \
367         __print_tstamp(buf, (es)->tstamp, (es)->tstamp ## _hi)
368
369 static ssize_t ext4_attr_show(struct kobject *kobj,
370                               struct attribute *attr, char *buf)
371 {
372         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
373                                                 s_kobj);
374         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
375         void *ptr = calc_ptr(a, sbi);
376
377         switch (a->attr_id) {
378         case attr_delayed_allocation_blocks:
379                 return sysfs_emit(buf, "%llu\n",
380                                 (s64) EXT4_C2B(sbi,
381                        percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
382         case attr_session_write_kbytes:
383                 return session_write_kbytes_show(sbi, buf);
384         case attr_lifetime_write_kbytes:
385                 return lifetime_write_kbytes_show(sbi, buf);
386         case attr_reserved_clusters:
387                 return sysfs_emit(buf, "%llu\n",
388                                 (unsigned long long)
389                                 atomic64_read(&sbi->s_resv_clusters));
390         case attr_sra_exceeded_retry_limit:
391                 return sysfs_emit(buf, "%llu\n",
392                                 (unsigned long long)
393                         percpu_counter_sum(&sbi->s_sra_exceeded_retry_limit));
394         case attr_inode_readahead:
395         case attr_pointer_ui:
396                 if (!ptr)
397                         return 0;
398                 if (a->attr_ptr == ptr_ext4_super_block_offset)
399                         return sysfs_emit(buf, "%u\n",
400                                         le32_to_cpup(ptr));
401                 else
402                         return sysfs_emit(buf, "%u\n",
403                                         *((unsigned int *) ptr));
404         case attr_pointer_ul:
405                 if (!ptr)
406                         return 0;
407                 return sysfs_emit(buf, "%lu\n",
408                                 *((unsigned long *) ptr));
409         case attr_pointer_u8:
410                 if (!ptr)
411                         return 0;
412                 return sysfs_emit(buf, "%u\n",
413                                 *((unsigned char *) ptr));
414         case attr_pointer_u64:
415                 if (!ptr)
416                         return 0;
417                 if (a->attr_ptr == ptr_ext4_super_block_offset)
418                         return sysfs_emit(buf, "%llu\n",
419                                         le64_to_cpup(ptr));
420                 else
421                         return sysfs_emit(buf, "%llu\n",
422                                         *((unsigned long long *) ptr));
423         case attr_pointer_string:
424                 if (!ptr)
425                         return 0;
426                 return sysfs_emit(buf, "%.*s\n", a->attr_size,
427                                 (char *) ptr);
428         case attr_pointer_atomic:
429                 if (!ptr)
430                         return 0;
431                 return sysfs_emit(buf, "%d\n",
432                                 atomic_read((atomic_t *) ptr));
433         case attr_feature:
434                 return sysfs_emit(buf, "supported\n");
435         case attr_first_error_time:
436                 return print_tstamp(buf, sbi->s_es, s_first_error_time);
437         case attr_last_error_time:
438                 return print_tstamp(buf, sbi->s_es, s_last_error_time);
439         case attr_journal_task:
440                 return journal_task_show(sbi, buf);
441         }
442
443         return 0;
444 }
445
446 static ssize_t ext4_attr_store(struct kobject *kobj,
447                                struct attribute *attr,
448                                const char *buf, size_t len)
449 {
450         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
451                                                 s_kobj);
452         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
453         void *ptr = calc_ptr(a, sbi);
454         unsigned long t;
455         int ret;
456
457         switch (a->attr_id) {
458         case attr_reserved_clusters:
459                 return reserved_clusters_store(sbi, buf, len);
460         case attr_pointer_ui:
461                 if (!ptr)
462                         return 0;
463                 ret = kstrtoul(skip_spaces(buf), 0, &t);
464                 if (ret)
465                         return ret;
466                 if (a->attr_ptr == ptr_ext4_super_block_offset)
467                         *((__le32 *) ptr) = cpu_to_le32(t);
468                 else
469                         *((unsigned int *) ptr) = t;
470                 return len;
471         case attr_pointer_ul:
472                 if (!ptr)
473                         return 0;
474                 ret = kstrtoul(skip_spaces(buf), 0, &t);
475                 if (ret)
476                         return ret;
477                 *((unsigned long *) ptr) = t;
478                 return len;
479         case attr_inode_readahead:
480                 return inode_readahead_blks_store(sbi, buf, len);
481         case attr_trigger_test_error:
482                 return trigger_test_error(sbi, buf, len);
483         }
484         return 0;
485 }
486
487 static void ext4_sb_release(struct kobject *kobj)
488 {
489         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
490                                                 s_kobj);
491         complete(&sbi->s_kobj_unregister);
492 }
493
494 static void ext4_feat_release(struct kobject *kobj)
495 {
496         kfree(kobj);
497 }
498
499 static const struct sysfs_ops ext4_attr_ops = {
500         .show   = ext4_attr_show,
501         .store  = ext4_attr_store,
502 };
503
504 static struct kobj_type ext4_sb_ktype = {
505         .default_groups = ext4_groups,
506         .sysfs_ops      = &ext4_attr_ops,
507         .release        = ext4_sb_release,
508 };
509
510 static struct kobj_type ext4_feat_ktype = {
511         .default_groups = ext4_feat_groups,
512         .sysfs_ops      = &ext4_attr_ops,
513         .release        = ext4_feat_release,
514 };
515
516 void ext4_notify_error_sysfs(struct ext4_sb_info *sbi)
517 {
518         sysfs_notify(&sbi->s_kobj, NULL, "errors_count");
519 }
520
521 static struct kobject *ext4_root;
522
523 static struct kobject *ext4_feat;
524
525 int ext4_register_sysfs(struct super_block *sb)
526 {
527         struct ext4_sb_info *sbi = EXT4_SB(sb);
528         int err;
529
530         init_completion(&sbi->s_kobj_unregister);
531         err = kobject_init_and_add(&sbi->s_kobj, &ext4_sb_ktype, ext4_root,
532                                    "%s", sb->s_id);
533         if (err) {
534                 kobject_put(&sbi->s_kobj);
535                 wait_for_completion(&sbi->s_kobj_unregister);
536                 return err;
537         }
538
539         if (ext4_proc_root)
540                 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
541         if (sbi->s_proc) {
542                 proc_create_single_data("options", S_IRUGO, sbi->s_proc,
543                                 ext4_seq_options_show, sb);
544                 proc_create_single_data("es_shrinker_info", S_IRUGO,
545                                 sbi->s_proc, ext4_seq_es_shrinker_info_show,
546                                 sb);
547                 proc_create_single_data("fc_info", 0444, sbi->s_proc,
548                                         ext4_fc_info_show, sb);
549                 proc_create_seq_data("mb_groups", S_IRUGO, sbi->s_proc,
550                                 &ext4_mb_seq_groups_ops, sb);
551                 proc_create_single_data("mb_stats", 0444, sbi->s_proc,
552                                 ext4_seq_mb_stats_show, sb);
553                 proc_create_seq_data("mb_structs_summary", 0444, sbi->s_proc,
554                                 &ext4_mb_seq_structs_summary_ops, sb);
555         }
556         return 0;
557 }
558
559 void ext4_unregister_sysfs(struct super_block *sb)
560 {
561         struct ext4_sb_info *sbi = EXT4_SB(sb);
562
563         if (sbi->s_proc)
564                 remove_proc_subtree(sb->s_id, ext4_proc_root);
565         kobject_del(&sbi->s_kobj);
566 }
567
568 int __init ext4_init_sysfs(void)
569 {
570         int ret;
571
572         ext4_root = kobject_create_and_add("ext4", fs_kobj);
573         if (!ext4_root)
574                 return -ENOMEM;
575
576         ext4_feat = kzalloc(sizeof(*ext4_feat), GFP_KERNEL);
577         if (!ext4_feat) {
578                 ret = -ENOMEM;
579                 goto root_err;
580         }
581
582         ret = kobject_init_and_add(ext4_feat, &ext4_feat_ktype,
583                                    ext4_root, "features");
584         if (ret)
585                 goto feat_err;
586
587         ext4_proc_root = proc_mkdir(proc_dirname, NULL);
588         return ret;
589
590 feat_err:
591         kobject_put(ext4_feat);
592         ext4_feat = NULL;
593 root_err:
594         kobject_put(ext4_root);
595         ext4_root = NULL;
596         return ret;
597 }
598
599 void ext4_exit_sysfs(void)
600 {
601         kobject_put(ext4_feat);
602         ext4_feat = NULL;
603         kobject_put(ext4_root);
604         ext4_root = NULL;
605         remove_proc_entry(proc_dirname, NULL);
606         ext4_proc_root = NULL;
607 }
608