xref: /openbmc/linux/fs/ext4/sysfs.c (revision 3d40aed8)
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_linear_groups, s_mb_max_linear_groups);
218 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
219 EXT4_ATTR(trigger_fs_error, 0200, trigger_test_error);
220 EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);
221 EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst);
222 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);
223 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst);
224 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval);
225 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst);
226 EXT4_RW_ATTR_SBI_UI(mb_best_avail_max_trim_order, s_mb_best_avail_max_trim_order);
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_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 };
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 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 
510 static 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 
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 
609