xref: /kernel/linux/linux-5.10/fs/ext4/sysfs.c (revision 8c2ecf20)
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	if (!sb->s_bdev->bd_part)
67		return snprintf(buf, PAGE_SIZE, "0\n");
68	return snprintf(buf, PAGE_SIZE, "%lu\n",
69			(part_stat_read(sb->s_bdev->bd_part,
70					sectors[STAT_WRITE]) -
71			 sbi->s_sectors_written_start) >> 1);
72}
73
74static ssize_t lifetime_write_kbytes_show(struct ext4_sb_info *sbi, char *buf)
75{
76	struct super_block *sb = sbi->s_buddy_cache->i_sb;
77
78	if (!sb->s_bdev->bd_part)
79		return snprintf(buf, PAGE_SIZE, "0\n");
80	return snprintf(buf, PAGE_SIZE, "%llu\n",
81			(unsigned long long)(sbi->s_kbytes_written +
82			((part_stat_read(sb->s_bdev->bd_part,
83					 sectors[STAT_WRITE]) -
84			  EXT4_SB(sb)->s_sectors_written_start) >> 1)));
85}
86
87static ssize_t inode_readahead_blks_store(struct ext4_sb_info *sbi,
88					  const char *buf, size_t count)
89{
90	unsigned long t;
91	int ret;
92
93	ret = kstrtoul(skip_spaces(buf), 0, &t);
94	if (ret)
95		return ret;
96
97	if (t && (!is_power_of_2(t) || t > 0x40000000))
98		return -EINVAL;
99
100	sbi->s_inode_readahead_blks = t;
101	return count;
102}
103
104static ssize_t reserved_clusters_store(struct ext4_sb_info *sbi,
105				   const char *buf, size_t count)
106{
107	unsigned long long val;
108	ext4_fsblk_t clusters = (ext4_blocks_count(sbi->s_es) >>
109				 sbi->s_cluster_bits);
110	int ret;
111
112	ret = kstrtoull(skip_spaces(buf), 0, &val);
113	if (ret || val >= clusters)
114		return -EINVAL;
115
116	atomic64_set(&sbi->s_resv_clusters, val);
117	return count;
118}
119
120static ssize_t trigger_test_error(struct ext4_sb_info *sbi,
121				  const char *buf, size_t count)
122{
123	int len = count;
124
125	if (!capable(CAP_SYS_ADMIN))
126		return -EPERM;
127
128	if (len && buf[len-1] == '\n')
129		len--;
130
131	if (len)
132		ext4_error(sbi->s_sb, "%.*s", len, buf);
133	return count;
134}
135
136static ssize_t journal_task_show(struct ext4_sb_info *sbi, char *buf)
137{
138	if (!sbi->s_journal)
139		return snprintf(buf, PAGE_SIZE, "<none>\n");
140	return snprintf(buf, PAGE_SIZE, "%d\n",
141			task_pid_vnr(sbi->s_journal->j_task));
142}
143
144#define EXT4_ATTR(_name,_mode,_id)					\
145static struct ext4_attr ext4_attr_##_name = {				\
146	.attr = {.name = __stringify(_name), .mode = _mode },		\
147	.attr_id = attr_##_id,						\
148}
149
150#define EXT4_ATTR_FUNC(_name,_mode)  EXT4_ATTR(_name,_mode,_name)
151
152#define EXT4_ATTR_FEATURE(_name)   EXT4_ATTR(_name, 0444, feature)
153
154#define EXT4_ATTR_OFFSET(_name,_mode,_id,_struct,_elname)	\
155static struct ext4_attr ext4_attr_##_name = {			\
156	.attr = {.name = __stringify(_name), .mode = _mode },	\
157	.attr_id = attr_##_id,					\
158	.attr_ptr = ptr_##_struct##_offset,			\
159	.u = {							\
160		.offset = offsetof(struct _struct, _elname),\
161	},							\
162}
163
164#define EXT4_ATTR_STRING(_name,_mode,_size,_struct,_elname)	\
165static struct ext4_attr ext4_attr_##_name = {			\
166	.attr = {.name = __stringify(_name), .mode = _mode },	\
167	.attr_id = attr_pointer_string,				\
168	.attr_size = _size,					\
169	.attr_ptr = ptr_##_struct##_offset,			\
170	.u = {							\
171		.offset = offsetof(struct _struct, _elname),\
172	},							\
173}
174
175#define EXT4_RO_ATTR_ES_UI(_name,_elname)				\
176	EXT4_ATTR_OFFSET(_name, 0444, pointer_ui, ext4_super_block, _elname)
177
178#define EXT4_RO_ATTR_ES_U8(_name,_elname)				\
179	EXT4_ATTR_OFFSET(_name, 0444, pointer_u8, ext4_super_block, _elname)
180
181#define EXT4_RO_ATTR_ES_U64(_name,_elname)				\
182	EXT4_ATTR_OFFSET(_name, 0444, pointer_u64, ext4_super_block, _elname)
183
184#define EXT4_RO_ATTR_ES_STRING(_name,_elname,_size)			\
185	EXT4_ATTR_STRING(_name, 0444, _size, ext4_super_block, _elname)
186
187#define EXT4_RW_ATTR_SBI_UI(_name,_elname)	\
188	EXT4_ATTR_OFFSET(_name, 0644, pointer_ui, ext4_sb_info, _elname)
189
190#define EXT4_RW_ATTR_SBI_UL(_name,_elname)	\
191	EXT4_ATTR_OFFSET(_name, 0644, pointer_ul, ext4_sb_info, _elname)
192
193#define EXT4_RO_ATTR_SBI_ATOMIC(_name,_elname)	\
194	EXT4_ATTR_OFFSET(_name, 0444, pointer_atomic, ext4_sb_info, _elname)
195
196#define EXT4_ATTR_PTR(_name,_mode,_id,_ptr) \
197static struct ext4_attr ext4_attr_##_name = {			\
198	.attr = {.name = __stringify(_name), .mode = _mode },	\
199	.attr_id = attr_##_id,					\
200	.attr_ptr = ptr_explicit,				\
201	.u = {							\
202		.explicit_ptr = _ptr,				\
203	},							\
204}
205
206#define ATTR_LIST(name) &ext4_attr_##name.attr
207
208EXT4_ATTR_FUNC(delayed_allocation_blocks, 0444);
209EXT4_ATTR_FUNC(session_write_kbytes, 0444);
210EXT4_ATTR_FUNC(lifetime_write_kbytes, 0444);
211EXT4_ATTR_FUNC(reserved_clusters, 0644);
212EXT4_ATTR_FUNC(sra_exceeded_retry_limit, 0444);
213
214EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, inode_readahead,
215		 ext4_sb_info, s_inode_readahead_blks);
216EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
217EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
218EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
219EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
220EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
221EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
222EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
223EXT4_RW_ATTR_SBI_UI(mb_max_inode_prealloc, s_mb_max_inode_prealloc);
224EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
225EXT4_ATTR(trigger_fs_error, 0200, trigger_test_error);
226EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);
227EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst);
228EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);
229EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst);
230EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval);
231EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst);
232#ifdef CONFIG_EXT4_DEBUG
233EXT4_RW_ATTR_SBI_UL(simulate_fail, s_simulate_fail);
234#endif
235EXT4_RO_ATTR_SBI_ATOMIC(warning_count, s_warning_count);
236EXT4_RO_ATTR_SBI_ATOMIC(msg_count, s_msg_count);
237EXT4_RO_ATTR_ES_UI(errors_count, s_error_count);
238EXT4_RO_ATTR_ES_U8(first_error_errcode, s_first_error_errcode);
239EXT4_RO_ATTR_ES_U8(last_error_errcode, s_last_error_errcode);
240EXT4_RO_ATTR_ES_UI(first_error_ino, s_first_error_ino);
241EXT4_RO_ATTR_ES_UI(last_error_ino, s_last_error_ino);
242EXT4_RO_ATTR_ES_U64(first_error_block, s_first_error_block);
243EXT4_RO_ATTR_ES_U64(last_error_block, s_last_error_block);
244EXT4_RO_ATTR_ES_UI(first_error_line, s_first_error_line);
245EXT4_RO_ATTR_ES_UI(last_error_line, s_last_error_line);
246EXT4_RO_ATTR_ES_STRING(first_error_func, s_first_error_func, 32);
247EXT4_RO_ATTR_ES_STRING(last_error_func, s_last_error_func, 32);
248EXT4_ATTR(first_error_time, 0444, first_error_time);
249EXT4_ATTR(last_error_time, 0444, last_error_time);
250EXT4_ATTR(journal_task, 0444, journal_task);
251EXT4_RW_ATTR_SBI_UI(mb_prefetch, s_mb_prefetch);
252EXT4_RW_ATTR_SBI_UI(mb_prefetch_limit, s_mb_prefetch_limit);
253
254static unsigned int old_bump_val = 128;
255EXT4_ATTR_PTR(max_writeback_mb_bump, 0444, pointer_ui, &old_bump_val);
256
257static struct attribute *ext4_attrs[] = {
258	ATTR_LIST(delayed_allocation_blocks),
259	ATTR_LIST(session_write_kbytes),
260	ATTR_LIST(lifetime_write_kbytes),
261	ATTR_LIST(reserved_clusters),
262	ATTR_LIST(sra_exceeded_retry_limit),
263	ATTR_LIST(inode_readahead_blks),
264	ATTR_LIST(inode_goal),
265	ATTR_LIST(mb_stats),
266	ATTR_LIST(mb_max_to_scan),
267	ATTR_LIST(mb_min_to_scan),
268	ATTR_LIST(mb_order2_req),
269	ATTR_LIST(mb_stream_req),
270	ATTR_LIST(mb_group_prealloc),
271	ATTR_LIST(mb_max_inode_prealloc),
272	ATTR_LIST(max_writeback_mb_bump),
273	ATTR_LIST(extent_max_zeroout_kb),
274	ATTR_LIST(trigger_fs_error),
275	ATTR_LIST(err_ratelimit_interval_ms),
276	ATTR_LIST(err_ratelimit_burst),
277	ATTR_LIST(warning_ratelimit_interval_ms),
278	ATTR_LIST(warning_ratelimit_burst),
279	ATTR_LIST(msg_ratelimit_interval_ms),
280	ATTR_LIST(msg_ratelimit_burst),
281	ATTR_LIST(errors_count),
282	ATTR_LIST(warning_count),
283	ATTR_LIST(msg_count),
284	ATTR_LIST(first_error_ino),
285	ATTR_LIST(last_error_ino),
286	ATTR_LIST(first_error_block),
287	ATTR_LIST(last_error_block),
288	ATTR_LIST(first_error_line),
289	ATTR_LIST(last_error_line),
290	ATTR_LIST(first_error_func),
291	ATTR_LIST(last_error_func),
292	ATTR_LIST(first_error_errcode),
293	ATTR_LIST(last_error_errcode),
294	ATTR_LIST(first_error_time),
295	ATTR_LIST(last_error_time),
296	ATTR_LIST(journal_task),
297#ifdef CONFIG_EXT4_DEBUG
298	ATTR_LIST(simulate_fail),
299#endif
300	ATTR_LIST(mb_prefetch),
301	ATTR_LIST(mb_prefetch_limit),
302	NULL,
303};
304ATTRIBUTE_GROUPS(ext4);
305
306/* Features this copy of ext4 supports */
307EXT4_ATTR_FEATURE(lazy_itable_init);
308EXT4_ATTR_FEATURE(batched_discard);
309EXT4_ATTR_FEATURE(meta_bg_resize);
310#ifdef CONFIG_FS_ENCRYPTION
311EXT4_ATTR_FEATURE(encryption);
312EXT4_ATTR_FEATURE(test_dummy_encryption_v2);
313#endif
314#ifdef CONFIG_UNICODE
315EXT4_ATTR_FEATURE(casefold);
316#endif
317#ifdef CONFIG_FS_VERITY
318EXT4_ATTR_FEATURE(verity);
319#endif
320EXT4_ATTR_FEATURE(metadata_csum_seed);
321EXT4_ATTR_FEATURE(fast_commit);
322
323static struct attribute *ext4_feat_attrs[] = {
324	ATTR_LIST(lazy_itable_init),
325	ATTR_LIST(batched_discard),
326	ATTR_LIST(meta_bg_resize),
327#ifdef CONFIG_FS_ENCRYPTION
328	ATTR_LIST(encryption),
329	ATTR_LIST(test_dummy_encryption_v2),
330#endif
331#ifdef CONFIG_UNICODE
332	ATTR_LIST(casefold),
333#endif
334#ifdef CONFIG_FS_VERITY
335	ATTR_LIST(verity),
336#endif
337	ATTR_LIST(metadata_csum_seed),
338	ATTR_LIST(fast_commit),
339	NULL,
340};
341ATTRIBUTE_GROUPS(ext4_feat);
342
343static void *calc_ptr(struct ext4_attr *a, struct ext4_sb_info *sbi)
344{
345	switch (a->attr_ptr) {
346	case ptr_explicit:
347		return a->u.explicit_ptr;
348	case ptr_ext4_sb_info_offset:
349		return (void *) (((char *) sbi) + a->u.offset);
350	case ptr_ext4_super_block_offset:
351		return (void *) (((char *) sbi->s_es) + a->u.offset);
352	}
353	return NULL;
354}
355
356static ssize_t __print_tstamp(char *buf, __le32 lo, __u8 hi)
357{
358	return snprintf(buf, PAGE_SIZE, "%lld\n",
359			((time64_t)hi << 32) + le32_to_cpu(lo));
360}
361
362#define print_tstamp(buf, es, tstamp) \
363	__print_tstamp(buf, (es)->tstamp, (es)->tstamp ## _hi)
364
365static ssize_t ext4_attr_show(struct kobject *kobj,
366			      struct attribute *attr, char *buf)
367{
368	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
369						s_kobj);
370	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
371	void *ptr = calc_ptr(a, sbi);
372
373	switch (a->attr_id) {
374	case attr_delayed_allocation_blocks:
375		return snprintf(buf, PAGE_SIZE, "%llu\n",
376				(s64) EXT4_C2B(sbi,
377		       percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
378	case attr_session_write_kbytes:
379		return session_write_kbytes_show(sbi, buf);
380	case attr_lifetime_write_kbytes:
381		return lifetime_write_kbytes_show(sbi, buf);
382	case attr_reserved_clusters:
383		return snprintf(buf, PAGE_SIZE, "%llu\n",
384				(unsigned long long)
385				atomic64_read(&sbi->s_resv_clusters));
386	case attr_sra_exceeded_retry_limit:
387		return snprintf(buf, PAGE_SIZE, "%llu\n",
388				(unsigned long long)
389			percpu_counter_sum(&sbi->s_sra_exceeded_retry_limit));
390	case attr_inode_readahead:
391	case attr_pointer_ui:
392		if (!ptr)
393			return 0;
394		if (a->attr_ptr == ptr_ext4_super_block_offset)
395			return snprintf(buf, PAGE_SIZE, "%u\n",
396					le32_to_cpup(ptr));
397		else
398			return snprintf(buf, PAGE_SIZE, "%u\n",
399					*((unsigned int *) ptr));
400	case attr_pointer_ul:
401		if (!ptr)
402			return 0;
403		return snprintf(buf, PAGE_SIZE, "%lu\n",
404				*((unsigned long *) ptr));
405	case attr_pointer_u8:
406		if (!ptr)
407			return 0;
408		return snprintf(buf, PAGE_SIZE, "%u\n",
409				*((unsigned char *) ptr));
410	case attr_pointer_u64:
411		if (!ptr)
412			return 0;
413		if (a->attr_ptr == ptr_ext4_super_block_offset)
414			return snprintf(buf, PAGE_SIZE, "%llu\n",
415					le64_to_cpup(ptr));
416		else
417			return snprintf(buf, PAGE_SIZE, "%llu\n",
418					*((unsigned long long *) ptr));
419	case attr_pointer_string:
420		if (!ptr)
421			return 0;
422		return snprintf(buf, PAGE_SIZE, "%.*s\n", a->attr_size,
423				(char *) ptr);
424	case attr_pointer_atomic:
425		if (!ptr)
426			return 0;
427		return snprintf(buf, PAGE_SIZE, "%d\n",
428				atomic_read((atomic_t *) ptr));
429	case attr_feature:
430		return snprintf(buf, PAGE_SIZE, "supported\n");
431	case attr_first_error_time:
432		return print_tstamp(buf, sbi->s_es, s_first_error_time);
433	case attr_last_error_time:
434		return print_tstamp(buf, sbi->s_es, s_last_error_time);
435	case attr_journal_task:
436		return journal_task_show(sbi, buf);
437	}
438
439	return 0;
440}
441
442static ssize_t ext4_attr_store(struct kobject *kobj,
443			       struct attribute *attr,
444			       const char *buf, size_t len)
445{
446	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
447						s_kobj);
448	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
449	void *ptr = calc_ptr(a, sbi);
450	unsigned long t;
451	int ret;
452
453	switch (a->attr_id) {
454	case attr_reserved_clusters:
455		return reserved_clusters_store(sbi, buf, len);
456	case attr_pointer_ui:
457		if (!ptr)
458			return 0;
459		ret = kstrtoul(skip_spaces(buf), 0, &t);
460		if (ret)
461			return ret;
462		if (a->attr_ptr == ptr_ext4_super_block_offset)
463			*((__le32 *) ptr) = cpu_to_le32(t);
464		else
465			*((unsigned int *) ptr) = t;
466		return len;
467	case attr_pointer_ul:
468		if (!ptr)
469			return 0;
470		ret = kstrtoul(skip_spaces(buf), 0, &t);
471		if (ret)
472			return ret;
473		*((unsigned long *) ptr) = t;
474		return len;
475	case attr_inode_readahead:
476		return inode_readahead_blks_store(sbi, buf, len);
477	case attr_trigger_test_error:
478		return trigger_test_error(sbi, buf, len);
479	}
480	return 0;
481}
482
483static void ext4_sb_release(struct kobject *kobj)
484{
485	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
486						s_kobj);
487	complete(&sbi->s_kobj_unregister);
488}
489
490static void ext4_feat_release(struct kobject *kobj)
491{
492	kfree(kobj);
493}
494
495static const struct sysfs_ops ext4_attr_ops = {
496	.show	= ext4_attr_show,
497	.store	= ext4_attr_store,
498};
499
500static struct kobj_type ext4_sb_ktype = {
501	.default_groups = ext4_groups,
502	.sysfs_ops	= &ext4_attr_ops,
503	.release	= ext4_sb_release,
504};
505
506static struct kobj_type ext4_feat_ktype = {
507	.default_groups = ext4_feat_groups,
508	.sysfs_ops	= &ext4_attr_ops,
509	.release	= ext4_feat_release,
510};
511
512static struct kobject *ext4_root;
513
514static struct kobject *ext4_feat;
515
516int ext4_register_sysfs(struct super_block *sb)
517{
518	struct ext4_sb_info *sbi = EXT4_SB(sb);
519	int err;
520
521	init_completion(&sbi->s_kobj_unregister);
522	err = kobject_init_and_add(&sbi->s_kobj, &ext4_sb_ktype, ext4_root,
523				   "%s", sb->s_id);
524	if (err) {
525		kobject_put(&sbi->s_kobj);
526		wait_for_completion(&sbi->s_kobj_unregister);
527		return err;
528	}
529
530	if (ext4_proc_root)
531		sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
532	if (sbi->s_proc) {
533		proc_create_single_data("options", S_IRUGO, sbi->s_proc,
534				ext4_seq_options_show, sb);
535		proc_create_single_data("es_shrinker_info", S_IRUGO,
536				sbi->s_proc, ext4_seq_es_shrinker_info_show,
537				sb);
538		proc_create_single_data("fc_info", 0444, sbi->s_proc,
539					ext4_fc_info_show, sb);
540		proc_create_seq_data("mb_groups", S_IRUGO, sbi->s_proc,
541				&ext4_mb_seq_groups_ops, sb);
542		proc_create_single_data("mb_stats", 0444, sbi->s_proc,
543				ext4_seq_mb_stats_show, sb);
544	}
545	return 0;
546}
547
548void ext4_unregister_sysfs(struct super_block *sb)
549{
550	struct ext4_sb_info *sbi = EXT4_SB(sb);
551
552	if (sbi->s_proc)
553		remove_proc_subtree(sb->s_id, ext4_proc_root);
554	kobject_del(&sbi->s_kobj);
555}
556
557int __init ext4_init_sysfs(void)
558{
559	int ret;
560
561	ext4_root = kobject_create_and_add("ext4", fs_kobj);
562	if (!ext4_root)
563		return -ENOMEM;
564
565	ext4_feat = kzalloc(sizeof(*ext4_feat), GFP_KERNEL);
566	if (!ext4_feat) {
567		ret = -ENOMEM;
568		goto root_err;
569	}
570
571	ret = kobject_init_and_add(ext4_feat, &ext4_feat_ktype,
572				   ext4_root, "features");
573	if (ret)
574		goto feat_err;
575
576	ext4_proc_root = proc_mkdir(proc_dirname, NULL);
577	return ret;
578
579feat_err:
580	kobject_put(ext4_feat);
581	ext4_feat = NULL;
582root_err:
583	kobject_put(ext4_root);
584	ext4_root = NULL;
585	return ret;
586}
587
588void ext4_exit_sysfs(void)
589{
590	kobject_put(ext4_feat);
591	ext4_feat = NULL;
592	kobject_put(ext4_root);
593	ext4_root = NULL;
594	remove_proc_entry(proc_dirname, NULL);
595	ext4_proc_root = NULL;
596}
597
598