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
21typedef 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
42typedef enum {
43 ptr_explicit,
44 ptr_ext4_sb_info_offset,
45 ptr_ext4_super_block_offset,
46} attr_ptr_t;
47
48static const char proc_dirname[] = "fs/ext4";
49static struct proc_dir_entry *ext4_proc_root;
50
51struct 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
62static 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, fmt: "%lu\n",
67 (part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
68 sbi->s_sectors_written_start) >> 1);
69}
70
71static 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, fmt: "%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
81static 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(s: skip_spaces(buf), base: 0, res: &t);
88 if (ret)
89 return ret;
90
91 if (t && (!is_power_of_2(n: t) || t > 0x40000000))
92 return -EINVAL;
93
94 sbi->s_inode_readahead_blks = t;
95 return count;
96}
97
98static 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(es: sbi->s_es) >>
103 sbi->s_cluster_bits);
104 int ret;
105
106 ret = kstrtoull(s: skip_spaces(buf), base: 0, res: &val);
107 if (ret || val >= clusters)
108 return -EINVAL;
109
110 atomic64_set(v: &sbi->s_resv_clusters, i: val);
111 return count;
112}
113
114static 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
130static ssize_t journal_task_show(struct ext4_sb_info *sbi, char *buf)
131{
132 if (!sbi->s_journal)
133 return sysfs_emit(buf, fmt: "<none>\n");
134 return sysfs_emit(buf, fmt: "%d\n",
135 task_pid_vnr(tsk: sbi->s_journal->j_task));
136}
137
138#define EXT4_ATTR(_name,_mode,_id) \
139static 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) \
149static 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) \
159static 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) \
191static 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
202EXT4_ATTR_FUNC(delayed_allocation_blocks, 0444);
203EXT4_ATTR_FUNC(session_write_kbytes, 0444);
204EXT4_ATTR_FUNC(lifetime_write_kbytes, 0444);
205EXT4_ATTR_FUNC(reserved_clusters, 0644);
206EXT4_ATTR_FUNC(sra_exceeded_retry_limit, 0444);
207
208EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, inode_readahead,
209 ext4_sb_info, s_inode_readahead_blks);
210EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
211EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
212EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
213EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
214EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
215EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
216EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
217EXT4_RW_ATTR_SBI_UI(mb_max_linear_groups, s_mb_max_linear_groups);
218EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
219EXT4_ATTR(trigger_fs_error, 0200, trigger_test_error);
220EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);
221EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst);
222EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);
223EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst);
224EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval);
225EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst);
226EXT4_RW_ATTR_SBI_UI(mb_best_avail_max_trim_order, s_mb_best_avail_max_trim_order);
227#ifdef CONFIG_EXT4_DEBUG
228EXT4_RW_ATTR_SBI_UL(simulate_fail, s_simulate_fail);
229#endif
230EXT4_RO_ATTR_SBI_ATOMIC(warning_count, s_warning_count);
231EXT4_RO_ATTR_SBI_ATOMIC(msg_count, s_msg_count);
232EXT4_RO_ATTR_ES_UI(errors_count, s_error_count);
233EXT4_RO_ATTR_ES_U8(first_error_errcode, s_first_error_errcode);
234EXT4_RO_ATTR_ES_U8(last_error_errcode, s_last_error_errcode);
235EXT4_RO_ATTR_ES_UI(first_error_ino, s_first_error_ino);
236EXT4_RO_ATTR_ES_UI(last_error_ino, s_last_error_ino);
237EXT4_RO_ATTR_ES_U64(first_error_block, s_first_error_block);
238EXT4_RO_ATTR_ES_U64(last_error_block, s_last_error_block);
239EXT4_RO_ATTR_ES_UI(first_error_line, s_first_error_line);
240EXT4_RO_ATTR_ES_UI(last_error_line, s_last_error_line);
241EXT4_RO_ATTR_ES_STRING(first_error_func, s_first_error_func, 32);
242EXT4_RO_ATTR_ES_STRING(last_error_func, s_last_error_func, 32);
243EXT4_ATTR(first_error_time, 0444, first_error_time);
244EXT4_ATTR(last_error_time, 0444, last_error_time);
245EXT4_ATTR(journal_task, 0444, journal_task);
246EXT4_RW_ATTR_SBI_UI(mb_prefetch, s_mb_prefetch);
247EXT4_RW_ATTR_SBI_UI(mb_prefetch_limit, s_mb_prefetch_limit);
248EXT4_RW_ATTR_SBI_UL(last_trim_minblks, s_last_trim_minblks);
249
250static unsigned int old_bump_val = 128;
251EXT4_ATTR_PTR(max_writeback_mb_bump, 0444, pointer_ui, &old_bump_val);
252
253static 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_linear_groups),
268 ATTR_LIST(max_writeback_mb_bump),
269 ATTR_LIST(extent_max_zeroout_kb),
270 ATTR_LIST(trigger_fs_error),
271 ATTR_LIST(err_ratelimit_interval_ms),
272 ATTR_LIST(err_ratelimit_burst),
273 ATTR_LIST(warning_ratelimit_interval_ms),
274 ATTR_LIST(warning_ratelimit_burst),
275 ATTR_LIST(msg_ratelimit_interval_ms),
276 ATTR_LIST(msg_ratelimit_burst),
277 ATTR_LIST(mb_best_avail_max_trim_order),
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};
302ATTRIBUTE_GROUPS(ext4);
303
304/* Features this copy of ext4 supports */
305EXT4_ATTR_FEATURE(lazy_itable_init);
306EXT4_ATTR_FEATURE(batched_discard);
307EXT4_ATTR_FEATURE(meta_bg_resize);
308#ifdef CONFIG_FS_ENCRYPTION
309EXT4_ATTR_FEATURE(encryption);
310EXT4_ATTR_FEATURE(test_dummy_encryption_v2);
311#endif
312#if IS_ENABLED(CONFIG_UNICODE)
313EXT4_ATTR_FEATURE(casefold);
314#endif
315#ifdef CONFIG_FS_VERITY
316EXT4_ATTR_FEATURE(verity);
317#endif
318EXT4_ATTR_FEATURE(metadata_csum_seed);
319EXT4_ATTR_FEATURE(fast_commit);
320#if IS_ENABLED(CONFIG_UNICODE) && defined(CONFIG_FS_ENCRYPTION)
321EXT4_ATTR_FEATURE(encrypted_casefold);
322#endif
323
324static 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};
345ATTRIBUTE_GROUPS(ext4_feat);
346
347static 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
360static ssize_t __print_tstamp(char *buf, __le32 lo, __u8 hi)
361{
362 return sysfs_emit(buf, fmt: "%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
369static 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, fmt: "%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, fmt: "%llu\n",
388 (unsigned long long)
389 atomic64_read(v: &sbi->s_resv_clusters));
390 case attr_sra_exceeded_retry_limit:
391 return sysfs_emit(buf, fmt: "%llu\n",
392 (unsigned long long)
393 percpu_counter_sum(fbc: &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, fmt: "%u\n",
400 le32_to_cpup(p: ptr));
401 else
402 return sysfs_emit(buf, fmt: "%u\n",
403 *((unsigned int *) ptr));
404 case attr_pointer_ul:
405 if (!ptr)
406 return 0;
407 return sysfs_emit(buf, fmt: "%lu\n",
408 *((unsigned long *) ptr));
409 case attr_pointer_u8:
410 if (!ptr)
411 return 0;
412 return sysfs_emit(buf, fmt: "%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, fmt: "%llu\n",
419 le64_to_cpup(p: ptr));
420 else
421 return sysfs_emit(buf, fmt: "%llu\n",
422 *((unsigned long long *) ptr));
423 case attr_pointer_string:
424 if (!ptr)
425 return 0;
426 return sysfs_emit(buf, fmt: "%.*s\n", a->attr_size,
427 (char *) ptr);
428 case attr_pointer_atomic:
429 if (!ptr)
430 return 0;
431 return sysfs_emit(buf, fmt: "%d\n",
432 atomic_read(v: (atomic_t *) ptr));
433 case attr_feature:
434 return sysfs_emit(buf, fmt: "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
446static 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, count: len);
460 case attr_pointer_ui:
461 if (!ptr)
462 return 0;
463 ret = kstrtoul(s: skip_spaces(buf), base: 0, res: &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(s: skip_spaces(buf), base: 0, res: &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, count: len);
481 case attr_trigger_test_error:
482 return trigger_test_error(sbi, buf, count: len);
483 }
484 return 0;
485}
486
487static 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
494static void ext4_feat_release(struct kobject *kobj)
495{
496 kfree(objp: kobj);
497}
498
499static const struct sysfs_ops ext4_attr_ops = {
500 .show = ext4_attr_show,
501 .store = ext4_attr_store,
502};
503
504static const struct kobj_type ext4_sb_ktype = {
505 .default_groups = ext4_groups,
506 .sysfs_ops = &ext4_attr_ops,
507 .release = ext4_sb_release,
508};
509
510static const 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
516void ext4_notify_error_sysfs(struct ext4_sb_info *sbi)
517{
518 sysfs_notify(kobj: &sbi->s_kobj, NULL, attr: "errors_count");
519}
520
521static struct kobject *ext4_root;
522
523static struct kobject *ext4_feat;
524
525int ext4_register_sysfs(struct super_block *sb)
526{
527 struct ext4_sb_info *sbi = EXT4_SB(sb);
528 int err;
529
530 init_completion(x: &sbi->s_kobj_unregister);
531 err = kobject_init_and_add(kobj: &sbi->s_kobj, ktype: &ext4_sb_ktype, parent: ext4_root,
532 fmt: "%s", sb->s_id);
533 if (err) {
534 kobject_put(kobj: &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(name: "options", S_IRUGO, parent: sbi->s_proc,
543 show: ext4_seq_options_show, data: sb);
544 proc_create_single_data(name: "es_shrinker_info", S_IRUGO,
545 parent: sbi->s_proc, show: ext4_seq_es_shrinker_info_show,
546 data: sb);
547 proc_create_single_data(name: "fc_info", mode: 0444, parent: sbi->s_proc,
548 show: ext4_fc_info_show, data: 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(name: "mb_stats", mode: 0444, parent: sbi->s_proc,
552 show: ext4_seq_mb_stats_show, data: 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
559void 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(kobj: &sbi->s_kobj);
566}
567
568int __init ext4_init_sysfs(void)
569{
570 int ret;
571
572 ext4_root = kobject_create_and_add(name: "ext4", parent: fs_kobj);
573 if (!ext4_root)
574 return -ENOMEM;
575
576 ext4_feat = kzalloc(size: sizeof(*ext4_feat), GFP_KERNEL);
577 if (!ext4_feat) {
578 ret = -ENOMEM;
579 goto root_err;
580 }
581
582 ret = kobject_init_and_add(kobj: ext4_feat, ktype: &ext4_feat_ktype,
583 parent: ext4_root, fmt: "features");
584 if (ret)
585 goto feat_err;
586
587 ext4_proc_root = proc_mkdir(proc_dirname, NULL);
588 return ret;
589
590feat_err:
591 kobject_put(kobj: ext4_feat);
592 ext4_feat = NULL;
593root_err:
594 kobject_put(kobj: ext4_root);
595 ext4_root = NULL;
596 return ret;
597}
598
599void ext4_exit_sysfs(void)
600{
601 kobject_put(kobj: ext4_feat);
602 ext4_feat = NULL;
603 kobject_put(kobj: ext4_root);
604 ext4_root = NULL;
605 remove_proc_entry(proc_dirname, NULL);
606 ext4_proc_root = NULL;
607}
608
609

source code of linux/fs/ext4/sysfs.c