xref: /openbmc/linux/fs/ext4/sysfs.c (revision abb84c46)
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_clusters_in_group,
33 	attr_feature,
34 	attr_pointer_ui,
35 	attr_pointer_ul,
36 	attr_pointer_u64,
37 	attr_pointer_u8,
38 	attr_pointer_string,
39 	attr_pointer_atomic,
40 	attr_journal_task,
41 } attr_id_t;
42 
43 typedef enum {
44 	ptr_explicit,
45 	ptr_ext4_sb_info_offset,
46 	ptr_ext4_super_block_offset,
47 } attr_ptr_t;
48 
49 static const char proc_dirname[] = "fs/ext4";
50 static struct proc_dir_entry *ext4_proc_root;
51 
52 struct ext4_attr {
53 	struct attribute attr;
54 	short attr_id;
55 	short attr_ptr;
56 	unsigned short attr_size;
57 	union {
58 		int offset;
59 		void *explicit_ptr;
60 	} u;
61 };
62 
63 static ssize_t session_write_kbytes_show(struct ext4_sb_info *sbi, char *buf)
64 {
65 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
66 
67 	return sysfs_emit(buf, "%lu\n",
68 			(part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
69 			 sbi->s_sectors_written_start) >> 1);
70 }
71 
72 static ssize_t lifetime_write_kbytes_show(struct ext4_sb_info *sbi, char *buf)
73 {
74 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
75 
76 	return sysfs_emit(buf, "%llu\n",
77 			(unsigned long long)(sbi->s_kbytes_written +
78 			((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
79 			  EXT4_SB(sb)->s_sectors_written_start) >> 1)));
80 }
81 
82 static ssize_t inode_readahead_blks_store(struct ext4_sb_info *sbi,
83 					  const char *buf, size_t count)
84 {
85 	unsigned long t;
86 	int ret;
87 
88 	ret = kstrtoul(skip_spaces(buf), 0, &t);
89 	if (ret)
90 		return ret;
91 
92 	if (t && (!is_power_of_2(t) || t > 0x40000000))
93 		return -EINVAL;
94 
95 	sbi->s_inode_readahead_blks = t;
96 	return count;
97 }
98 
99 static ssize_t reserved_clusters_store(struct ext4_sb_info *sbi,
100 				   const char *buf, size_t count)
101 {
102 	unsigned long long val;
103 	ext4_fsblk_t clusters = (ext4_blocks_count(sbi->s_es) >>
104 				 sbi->s_cluster_bits);
105 	int ret;
106 
107 	ret = kstrtoull(skip_spaces(buf), 0, &val);
108 	if (ret || val >= clusters || (s64)val < 0)
109 		return -EINVAL;
110 
111 	atomic64_set(&sbi->s_resv_clusters, val);
112 	return count;
113 }
114 
115 static ssize_t trigger_test_error(struct ext4_sb_info *sbi,
116 				  const char *buf, size_t count)
117 {
118 	int len = count;
119 
120 	if (!capable(CAP_SYS_ADMIN))
121 		return -EPERM;
122 
123 	if (len && buf[len-1] == '\n')
124 		len--;
125 
126 	if (len)
127 		ext4_error(sbi->s_sb, "%.*s", len, buf);
128 	return count;
129 }
130 
131 static ssize_t journal_task_show(struct ext4_sb_info *sbi, char *buf)
132 {
133 	if (!sbi->s_journal)
134 		return sysfs_emit(buf, "<none>\n");
135 	return sysfs_emit(buf, "%d\n",
136 			task_pid_vnr(sbi->s_journal->j_task));
137 }
138 
139 #define EXT4_ATTR(_name,_mode,_id)					\
140 static struct ext4_attr ext4_attr_##_name = {				\
141 	.attr = {.name = __stringify(_name), .mode = _mode },		\
142 	.attr_id = attr_##_id,						\
143 }
144 
145 #define EXT4_ATTR_FUNC(_name,_mode)  EXT4_ATTR(_name,_mode,_name)
146 
147 #define EXT4_ATTR_FEATURE(_name)   EXT4_ATTR(_name, 0444, feature)
148 
149 #define EXT4_ATTR_OFFSET(_name,_mode,_id,_struct,_elname)	\
150 static struct ext4_attr ext4_attr_##_name = {			\
151 	.attr = {.name = __stringify(_name), .mode = _mode },	\
152 	.attr_id = attr_##_id,					\
153 	.attr_ptr = ptr_##_struct##_offset,			\
154 	.u = {							\
155 		.offset = offsetof(struct _struct, _elname),\
156 	},							\
157 }
158 
159 #define EXT4_ATTR_STRING(_name,_mode,_size,_struct,_elname)	\
160 static struct ext4_attr ext4_attr_##_name = {			\
161 	.attr = {.name = __stringify(_name), .mode = _mode },	\
162 	.attr_id = attr_pointer_string,				\
163 	.attr_size = _size,					\
164 	.attr_ptr = ptr_##_struct##_offset,			\
165 	.u = {							\
166 		.offset = offsetof(struct _struct, _elname),\
167 	},							\
168 }
169 
170 #define EXT4_RO_ATTR_ES_UI(_name,_elname)				\
171 	EXT4_ATTR_OFFSET(_name, 0444, pointer_ui, ext4_super_block, _elname)
172 
173 #define EXT4_RO_ATTR_ES_U8(_name,_elname)				\
174 	EXT4_ATTR_OFFSET(_name, 0444, pointer_u8, ext4_super_block, _elname)
175 
176 #define EXT4_RO_ATTR_ES_U64(_name,_elname)				\
177 	EXT4_ATTR_OFFSET(_name, 0444, pointer_u64, ext4_super_block, _elname)
178 
179 #define EXT4_RO_ATTR_ES_STRING(_name,_elname,_size)			\
180 	EXT4_ATTR_STRING(_name, 0444, _size, ext4_super_block, _elname)
181 
182 #define EXT4_RW_ATTR_SBI_UI(_name,_elname)	\
183 	EXT4_ATTR_OFFSET(_name, 0644, pointer_ui, ext4_sb_info, _elname)
184 
185 #define EXT4_RW_ATTR_SBI_UL(_name,_elname)	\
186 	EXT4_ATTR_OFFSET(_name, 0644, pointer_ul, ext4_sb_info, _elname)
187 
188 #define EXT4_RO_ATTR_SBI_ATOMIC(_name,_elname)	\
189 	EXT4_ATTR_OFFSET(_name, 0444, pointer_atomic, ext4_sb_info, _elname)
190 
191 #define EXT4_ATTR_PTR(_name,_mode,_id,_ptr) \
192 static struct ext4_attr ext4_attr_##_name = {			\
193 	.attr = {.name = __stringify(_name), .mode = _mode },	\
194 	.attr_id = attr_##_id,					\
195 	.attr_ptr = ptr_explicit,				\
196 	.u = {							\
197 		.explicit_ptr = _ptr,				\
198 	},							\
199 }
200 
201 #define ATTR_LIST(name) &ext4_attr_##name.attr
202 
203 EXT4_ATTR_FUNC(delayed_allocation_blocks, 0444);
204 EXT4_ATTR_FUNC(session_write_kbytes, 0444);
205 EXT4_ATTR_FUNC(lifetime_write_kbytes, 0444);
206 EXT4_ATTR_FUNC(reserved_clusters, 0644);
207 EXT4_ATTR_FUNC(sra_exceeded_retry_limit, 0444);
208 
209 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, inode_readahead,
210 		 ext4_sb_info, s_inode_readahead_blks);
211 EXT4_ATTR_OFFSET(mb_group_prealloc, 0644, clusters_in_group,
212 		 ext4_sb_info, s_mb_group_prealloc);
213 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
214 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
215 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
216 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
217 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
218 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
219 EXT4_RW_ATTR_SBI_UI(mb_max_linear_groups, s_mb_max_linear_groups);
220 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
221 EXT4_ATTR(trigger_fs_error, 0200, trigger_test_error);
222 EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);
223 EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst);
224 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);
225 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst);
226 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval);
227 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst);
228 EXT4_RW_ATTR_SBI_UI(mb_best_avail_max_trim_order, s_mb_best_avail_max_trim_order);
229 #ifdef CONFIG_EXT4_DEBUG
230 EXT4_RW_ATTR_SBI_UL(simulate_fail, s_simulate_fail);
231 #endif
232 EXT4_RO_ATTR_SBI_ATOMIC(warning_count, s_warning_count);
233 EXT4_RO_ATTR_SBI_ATOMIC(msg_count, s_msg_count);
234 EXT4_RO_ATTR_ES_UI(errors_count, s_error_count);
235 EXT4_RO_ATTR_ES_U8(first_error_errcode, s_first_error_errcode);
236 EXT4_RO_ATTR_ES_U8(last_error_errcode, s_last_error_errcode);
237 EXT4_RO_ATTR_ES_UI(first_error_ino, s_first_error_ino);
238 EXT4_RO_ATTR_ES_UI(last_error_ino, s_last_error_ino);
239 EXT4_RO_ATTR_ES_U64(first_error_block, s_first_error_block);
240 EXT4_RO_ATTR_ES_U64(last_error_block, s_last_error_block);
241 EXT4_RO_ATTR_ES_UI(first_error_line, s_first_error_line);
242 EXT4_RO_ATTR_ES_UI(last_error_line, s_last_error_line);
243 EXT4_RO_ATTR_ES_STRING(first_error_func, s_first_error_func, 32);
244 EXT4_RO_ATTR_ES_STRING(last_error_func, s_last_error_func, 32);
245 EXT4_ATTR(first_error_time, 0444, first_error_time);
246 EXT4_ATTR(last_error_time, 0444, last_error_time);
247 EXT4_ATTR(journal_task, 0444, journal_task);
248 EXT4_RW_ATTR_SBI_UI(mb_prefetch, s_mb_prefetch);
249 EXT4_RW_ATTR_SBI_UI(mb_prefetch_limit, s_mb_prefetch_limit);
250 EXT4_RW_ATTR_SBI_UL(last_trim_minblks, s_last_trim_minblks);
251 
252 static unsigned int old_bump_val = 128;
253 EXT4_ATTR_PTR(max_writeback_mb_bump, 0444, pointer_ui, &old_bump_val);
254 
255 static struct attribute *ext4_attrs[] = {
256 	ATTR_LIST(delayed_allocation_blocks),
257 	ATTR_LIST(session_write_kbytes),
258 	ATTR_LIST(lifetime_write_kbytes),
259 	ATTR_LIST(reserved_clusters),
260 	ATTR_LIST(sra_exceeded_retry_limit),
261 	ATTR_LIST(inode_readahead_blks),
262 	ATTR_LIST(inode_goal),
263 	ATTR_LIST(mb_stats),
264 	ATTR_LIST(mb_max_to_scan),
265 	ATTR_LIST(mb_min_to_scan),
266 	ATTR_LIST(mb_order2_req),
267 	ATTR_LIST(mb_stream_req),
268 	ATTR_LIST(mb_group_prealloc),
269 	ATTR_LIST(mb_max_linear_groups),
270 	ATTR_LIST(max_writeback_mb_bump),
271 	ATTR_LIST(extent_max_zeroout_kb),
272 	ATTR_LIST(trigger_fs_error),
273 	ATTR_LIST(err_ratelimit_interval_ms),
274 	ATTR_LIST(err_ratelimit_burst),
275 	ATTR_LIST(warning_ratelimit_interval_ms),
276 	ATTR_LIST(warning_ratelimit_burst),
277 	ATTR_LIST(msg_ratelimit_interval_ms),
278 	ATTR_LIST(msg_ratelimit_burst),
279 	ATTR_LIST(mb_best_avail_max_trim_order),
280 	ATTR_LIST(errors_count),
281 	ATTR_LIST(warning_count),
282 	ATTR_LIST(msg_count),
283 	ATTR_LIST(first_error_ino),
284 	ATTR_LIST(last_error_ino),
285 	ATTR_LIST(first_error_block),
286 	ATTR_LIST(last_error_block),
287 	ATTR_LIST(first_error_line),
288 	ATTR_LIST(last_error_line),
289 	ATTR_LIST(first_error_func),
290 	ATTR_LIST(last_error_func),
291 	ATTR_LIST(first_error_errcode),
292 	ATTR_LIST(last_error_errcode),
293 	ATTR_LIST(first_error_time),
294 	ATTR_LIST(last_error_time),
295 	ATTR_LIST(journal_task),
296 #ifdef CONFIG_EXT4_DEBUG
297 	ATTR_LIST(simulate_fail),
298 #endif
299 	ATTR_LIST(mb_prefetch),
300 	ATTR_LIST(mb_prefetch_limit),
301 	ATTR_LIST(last_trim_minblks),
302 	NULL,
303 };
304 ATTRIBUTE_GROUPS(ext4);
305 
306 /* Features this copy of ext4 supports */
307 EXT4_ATTR_FEATURE(lazy_itable_init);
308 EXT4_ATTR_FEATURE(batched_discard);
309 EXT4_ATTR_FEATURE(meta_bg_resize);
310 #ifdef CONFIG_FS_ENCRYPTION
311 EXT4_ATTR_FEATURE(encryption);
312 EXT4_ATTR_FEATURE(test_dummy_encryption_v2);
313 #endif
314 #if IS_ENABLED(CONFIG_UNICODE)
315 EXT4_ATTR_FEATURE(casefold);
316 #endif
317 #ifdef CONFIG_FS_VERITY
318 EXT4_ATTR_FEATURE(verity);
319 #endif
320 EXT4_ATTR_FEATURE(metadata_csum_seed);
321 EXT4_ATTR_FEATURE(fast_commit);
322 #if IS_ENABLED(CONFIG_UNICODE) && defined(CONFIG_FS_ENCRYPTION)
323 EXT4_ATTR_FEATURE(encrypted_casefold);
324 #endif
325 
326 static struct attribute *ext4_feat_attrs[] = {
327 	ATTR_LIST(lazy_itable_init),
328 	ATTR_LIST(batched_discard),
329 	ATTR_LIST(meta_bg_resize),
330 #ifdef CONFIG_FS_ENCRYPTION
331 	ATTR_LIST(encryption),
332 	ATTR_LIST(test_dummy_encryption_v2),
333 #endif
334 #if IS_ENABLED(CONFIG_UNICODE)
335 	ATTR_LIST(casefold),
336 #endif
337 #ifdef CONFIG_FS_VERITY
338 	ATTR_LIST(verity),
339 #endif
340 	ATTR_LIST(metadata_csum_seed),
341 	ATTR_LIST(fast_commit),
342 #if IS_ENABLED(CONFIG_UNICODE) && defined(CONFIG_FS_ENCRYPTION)
343 	ATTR_LIST(encrypted_casefold),
344 #endif
345 	NULL,
346 };
347 ATTRIBUTE_GROUPS(ext4_feat);
348 
349 static void *calc_ptr(struct ext4_attr *a, struct ext4_sb_info *sbi)
350 {
351 	switch (a->attr_ptr) {
352 	case ptr_explicit:
353 		return a->u.explicit_ptr;
354 	case ptr_ext4_sb_info_offset:
355 		return (void *) (((char *) sbi) + a->u.offset);
356 	case ptr_ext4_super_block_offset:
357 		return (void *) (((char *) sbi->s_es) + a->u.offset);
358 	}
359 	return NULL;
360 }
361 
362 static ssize_t __print_tstamp(char *buf, __le32 lo, __u8 hi)
363 {
364 	return sysfs_emit(buf, "%lld\n",
365 			((time64_t)hi << 32) + le32_to_cpu(lo));
366 }
367 
368 #define print_tstamp(buf, es, tstamp) \
369 	__print_tstamp(buf, (es)->tstamp, (es)->tstamp ## _hi)
370 
371 static ssize_t ext4_attr_show(struct kobject *kobj,
372 			      struct attribute *attr, char *buf)
373 {
374 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
375 						s_kobj);
376 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
377 	void *ptr = calc_ptr(a, sbi);
378 
379 	switch (a->attr_id) {
380 	case attr_delayed_allocation_blocks:
381 		return sysfs_emit(buf, "%llu\n",
382 				(s64) EXT4_C2B(sbi,
383 		       percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
384 	case attr_session_write_kbytes:
385 		return session_write_kbytes_show(sbi, buf);
386 	case attr_lifetime_write_kbytes:
387 		return lifetime_write_kbytes_show(sbi, buf);
388 	case attr_reserved_clusters:
389 		return sysfs_emit(buf, "%llu\n",
390 				(unsigned long long)
391 				atomic64_read(&sbi->s_resv_clusters));
392 	case attr_sra_exceeded_retry_limit:
393 		return sysfs_emit(buf, "%llu\n",
394 				(unsigned long long)
395 			percpu_counter_sum(&sbi->s_sra_exceeded_retry_limit));
396 	case attr_inode_readahead:
397 	case attr_clusters_in_group:
398 	case attr_pointer_ui:
399 		if (!ptr)
400 			return 0;
401 		if (a->attr_ptr == ptr_ext4_super_block_offset)
402 			return sysfs_emit(buf, "%u\n",
403 					le32_to_cpup(ptr));
404 		else
405 			return sysfs_emit(buf, "%u\n",
406 					*((unsigned int *) ptr));
407 	case attr_pointer_ul:
408 		if (!ptr)
409 			return 0;
410 		return sysfs_emit(buf, "%lu\n",
411 				*((unsigned long *) ptr));
412 	case attr_pointer_u8:
413 		if (!ptr)
414 			return 0;
415 		return sysfs_emit(buf, "%u\n",
416 				*((unsigned char *) ptr));
417 	case attr_pointer_u64:
418 		if (!ptr)
419 			return 0;
420 		if (a->attr_ptr == ptr_ext4_super_block_offset)
421 			return sysfs_emit(buf, "%llu\n",
422 					le64_to_cpup(ptr));
423 		else
424 			return sysfs_emit(buf, "%llu\n",
425 					*((unsigned long long *) ptr));
426 	case attr_pointer_string:
427 		if (!ptr)
428 			return 0;
429 		return sysfs_emit(buf, "%.*s\n", a->attr_size,
430 				(char *) ptr);
431 	case attr_pointer_atomic:
432 		if (!ptr)
433 			return 0;
434 		return sysfs_emit(buf, "%d\n",
435 				atomic_read((atomic_t *) ptr));
436 	case attr_feature:
437 		return sysfs_emit(buf, "supported\n");
438 	case attr_first_error_time:
439 		return print_tstamp(buf, sbi->s_es, s_first_error_time);
440 	case attr_last_error_time:
441 		return print_tstamp(buf, sbi->s_es, s_last_error_time);
442 	case attr_journal_task:
443 		return journal_task_show(sbi, buf);
444 	}
445 
446 	return 0;
447 }
448 
449 static ssize_t ext4_attr_store(struct kobject *kobj,
450 			       struct attribute *attr,
451 			       const char *buf, size_t len)
452 {
453 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
454 						s_kobj);
455 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
456 	void *ptr = calc_ptr(a, sbi);
457 	unsigned int t;
458 	unsigned long lt;
459 	int ret;
460 
461 	switch (a->attr_id) {
462 	case attr_reserved_clusters:
463 		return reserved_clusters_store(sbi, buf, len);
464 	case attr_pointer_ui:
465 		if (!ptr)
466 			return 0;
467 		ret = kstrtouint(skip_spaces(buf), 0, &t);
468 		if (ret)
469 			return ret;
470 		if (a->attr_ptr == ptr_ext4_super_block_offset)
471 			*((__le32 *) ptr) = cpu_to_le32(t);
472 		else
473 			*((unsigned int *) ptr) = t;
474 		return len;
475 	case attr_clusters_in_group:
476 		ret = kstrtouint(skip_spaces(buf), 0, &t);
477 		if (ret)
478 			return ret;
479 		if (t > sbi->s_clusters_per_group)
480 			return -EINVAL;
481 		*((unsigned int *) ptr) = t;
482 		return len;
483 	case attr_pointer_ul:
484 		if (!ptr)
485 			return 0;
486 		ret = kstrtoul(skip_spaces(buf), 0, &lt);
487 		if (ret)
488 			return ret;
489 		*((unsigned long *) ptr) = lt;
490 		return len;
491 	case attr_inode_readahead:
492 		return inode_readahead_blks_store(sbi, buf, len);
493 	case attr_trigger_test_error:
494 		return trigger_test_error(sbi, buf, len);
495 	}
496 	return 0;
497 }
498 
499 static void ext4_sb_release(struct kobject *kobj)
500 {
501 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
502 						s_kobj);
503 	complete(&sbi->s_kobj_unregister);
504 }
505 
506 static void ext4_feat_release(struct kobject *kobj)
507 {
508 	kfree(kobj);
509 }
510 
511 static const struct sysfs_ops ext4_attr_ops = {
512 	.show	= ext4_attr_show,
513 	.store	= ext4_attr_store,
514 };
515 
516 static const struct kobj_type ext4_sb_ktype = {
517 	.default_groups = ext4_groups,
518 	.sysfs_ops	= &ext4_attr_ops,
519 	.release	= ext4_sb_release,
520 };
521 
522 static const struct kobj_type ext4_feat_ktype = {
523 	.default_groups = ext4_feat_groups,
524 	.sysfs_ops	= &ext4_attr_ops,
525 	.release	= ext4_feat_release,
526 };
527 
528 void ext4_notify_error_sysfs(struct ext4_sb_info *sbi)
529 {
530 	sysfs_notify(&sbi->s_kobj, NULL, "errors_count");
531 }
532 
533 static struct kobject *ext4_root;
534 
535 static struct kobject *ext4_feat;
536 
537 int ext4_register_sysfs(struct super_block *sb)
538 {
539 	struct ext4_sb_info *sbi = EXT4_SB(sb);
540 	int err;
541 
542 	init_completion(&sbi->s_kobj_unregister);
543 	err = kobject_init_and_add(&sbi->s_kobj, &ext4_sb_ktype, ext4_root,
544 				   "%s", sb->s_id);
545 	if (err) {
546 		kobject_put(&sbi->s_kobj);
547 		wait_for_completion(&sbi->s_kobj_unregister);
548 		return err;
549 	}
550 
551 	if (ext4_proc_root)
552 		sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
553 	if (sbi->s_proc) {
554 		proc_create_single_data("options", S_IRUGO, sbi->s_proc,
555 				ext4_seq_options_show, sb);
556 		proc_create_single_data("es_shrinker_info", S_IRUGO,
557 				sbi->s_proc, ext4_seq_es_shrinker_info_show,
558 				sb);
559 		proc_create_single_data("fc_info", 0444, sbi->s_proc,
560 					ext4_fc_info_show, sb);
561 		proc_create_seq_data("mb_groups", S_IRUGO, sbi->s_proc,
562 				&ext4_mb_seq_groups_ops, sb);
563 		proc_create_single_data("mb_stats", 0444, sbi->s_proc,
564 				ext4_seq_mb_stats_show, sb);
565 		proc_create_seq_data("mb_structs_summary", 0444, sbi->s_proc,
566 				&ext4_mb_seq_structs_summary_ops, sb);
567 	}
568 	return 0;
569 }
570 
571 void ext4_unregister_sysfs(struct super_block *sb)
572 {
573 	struct ext4_sb_info *sbi = EXT4_SB(sb);
574 
575 	if (sbi->s_proc)
576 		remove_proc_subtree(sb->s_id, ext4_proc_root);
577 	kobject_del(&sbi->s_kobj);
578 }
579 
580 int __init ext4_init_sysfs(void)
581 {
582 	int ret;
583 
584 	ext4_root = kobject_create_and_add("ext4", fs_kobj);
585 	if (!ext4_root)
586 		return -ENOMEM;
587 
588 	ext4_feat = kzalloc(sizeof(*ext4_feat), GFP_KERNEL);
589 	if (!ext4_feat) {
590 		ret = -ENOMEM;
591 		goto root_err;
592 	}
593 
594 	ret = kobject_init_and_add(ext4_feat, &ext4_feat_ktype,
595 				   ext4_root, "features");
596 	if (ret)
597 		goto feat_err;
598 
599 	ext4_proc_root = proc_mkdir(proc_dirname, NULL);
600 	return ret;
601 
602 feat_err:
603 	kobject_put(ext4_feat);
604 	ext4_feat = NULL;
605 root_err:
606 	kobject_put(ext4_root);
607 	ext4_root = NULL;
608 	return ret;
609 }
610 
611 void ext4_exit_sysfs(void)
612 {
613 	kobject_put(ext4_feat);
614 	ext4_feat = NULL;
615 	kobject_put(ext4_root);
616 	ext4_root = NULL;
617 	remove_proc_entry(proc_dirname, NULL);
618 	ext4_proc_root = NULL;
619 }
620 
621