xref: /openbmc/linux/fs/ext4/sysfs.c (revision 7c2435ef)
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 #ifdef CONFIG_EXT4_DEBUG
227 EXT4_RW_ATTR_SBI_UL(simulate_fail, s_simulate_fail);
228 #endif
229 EXT4_RO_ATTR_SBI_ATOMIC(warning_count, s_warning_count);
230 EXT4_RO_ATTR_SBI_ATOMIC(msg_count, s_msg_count);
231 EXT4_RO_ATTR_ES_UI(errors_count, s_error_count);
232 EXT4_RO_ATTR_ES_U8(first_error_errcode, s_first_error_errcode);
233 EXT4_RO_ATTR_ES_U8(last_error_errcode, s_last_error_errcode);
234 EXT4_RO_ATTR_ES_UI(first_error_ino, s_first_error_ino);
235 EXT4_RO_ATTR_ES_UI(last_error_ino, s_last_error_ino);
236 EXT4_RO_ATTR_ES_U64(first_error_block, s_first_error_block);
237 EXT4_RO_ATTR_ES_U64(last_error_block, s_last_error_block);
238 EXT4_RO_ATTR_ES_UI(first_error_line, s_first_error_line);
239 EXT4_RO_ATTR_ES_UI(last_error_line, s_last_error_line);
240 EXT4_RO_ATTR_ES_STRING(first_error_func, s_first_error_func, 32);
241 EXT4_RO_ATTR_ES_STRING(last_error_func, s_last_error_func, 32);
242 EXT4_ATTR(first_error_time, 0444, first_error_time);
243 EXT4_ATTR(last_error_time, 0444, last_error_time);
244 EXT4_ATTR(journal_task, 0444, journal_task);
245 EXT4_RW_ATTR_SBI_UI(mb_prefetch, s_mb_prefetch);
246 EXT4_RW_ATTR_SBI_UI(mb_prefetch_limit, s_mb_prefetch_limit);
247 EXT4_RW_ATTR_SBI_UL(last_trim_minblks, s_last_trim_minblks);
248 
249 static unsigned int old_bump_val = 128;
250 EXT4_ATTR_PTR(max_writeback_mb_bump, 0444, pointer_ui, &old_bump_val);
251 
252 static struct attribute *ext4_attrs[] = {
253 	ATTR_LIST(delayed_allocation_blocks),
254 	ATTR_LIST(session_write_kbytes),
255 	ATTR_LIST(lifetime_write_kbytes),
256 	ATTR_LIST(reserved_clusters),
257 	ATTR_LIST(sra_exceeded_retry_limit),
258 	ATTR_LIST(inode_readahead_blks),
259 	ATTR_LIST(inode_goal),
260 	ATTR_LIST(mb_stats),
261 	ATTR_LIST(mb_max_to_scan),
262 	ATTR_LIST(mb_min_to_scan),
263 	ATTR_LIST(mb_order2_req),
264 	ATTR_LIST(mb_stream_req),
265 	ATTR_LIST(mb_group_prealloc),
266 	ATTR_LIST(mb_max_linear_groups),
267 	ATTR_LIST(max_writeback_mb_bump),
268 	ATTR_LIST(extent_max_zeroout_kb),
269 	ATTR_LIST(trigger_fs_error),
270 	ATTR_LIST(err_ratelimit_interval_ms),
271 	ATTR_LIST(err_ratelimit_burst),
272 	ATTR_LIST(warning_ratelimit_interval_ms),
273 	ATTR_LIST(warning_ratelimit_burst),
274 	ATTR_LIST(msg_ratelimit_interval_ms),
275 	ATTR_LIST(msg_ratelimit_burst),
276 	ATTR_LIST(errors_count),
277 	ATTR_LIST(warning_count),
278 	ATTR_LIST(msg_count),
279 	ATTR_LIST(first_error_ino),
280 	ATTR_LIST(last_error_ino),
281 	ATTR_LIST(first_error_block),
282 	ATTR_LIST(last_error_block),
283 	ATTR_LIST(first_error_line),
284 	ATTR_LIST(last_error_line),
285 	ATTR_LIST(first_error_func),
286 	ATTR_LIST(last_error_func),
287 	ATTR_LIST(first_error_errcode),
288 	ATTR_LIST(last_error_errcode),
289 	ATTR_LIST(first_error_time),
290 	ATTR_LIST(last_error_time),
291 	ATTR_LIST(journal_task),
292 #ifdef CONFIG_EXT4_DEBUG
293 	ATTR_LIST(simulate_fail),
294 #endif
295 	ATTR_LIST(mb_prefetch),
296 	ATTR_LIST(mb_prefetch_limit),
297 	ATTR_LIST(last_trim_minblks),
298 	NULL,
299 };
300 ATTRIBUTE_GROUPS(ext4);
301 
302 /* Features this copy of ext4 supports */
303 EXT4_ATTR_FEATURE(lazy_itable_init);
304 EXT4_ATTR_FEATURE(batched_discard);
305 EXT4_ATTR_FEATURE(meta_bg_resize);
306 #ifdef CONFIG_FS_ENCRYPTION
307 EXT4_ATTR_FEATURE(encryption);
308 EXT4_ATTR_FEATURE(test_dummy_encryption_v2);
309 #endif
310 #if IS_ENABLED(CONFIG_UNICODE)
311 EXT4_ATTR_FEATURE(casefold);
312 #endif
313 #ifdef CONFIG_FS_VERITY
314 EXT4_ATTR_FEATURE(verity);
315 #endif
316 EXT4_ATTR_FEATURE(metadata_csum_seed);
317 EXT4_ATTR_FEATURE(fast_commit);
318 #if IS_ENABLED(CONFIG_UNICODE) && defined(CONFIG_FS_ENCRYPTION)
319 EXT4_ATTR_FEATURE(encrypted_casefold);
320 #endif
321 
322 static struct attribute *ext4_feat_attrs[] = {
323 	ATTR_LIST(lazy_itable_init),
324 	ATTR_LIST(batched_discard),
325 	ATTR_LIST(meta_bg_resize),
326 #ifdef CONFIG_FS_ENCRYPTION
327 	ATTR_LIST(encryption),
328 	ATTR_LIST(test_dummy_encryption_v2),
329 #endif
330 #if IS_ENABLED(CONFIG_UNICODE)
331 	ATTR_LIST(casefold),
332 #endif
333 #ifdef CONFIG_FS_VERITY
334 	ATTR_LIST(verity),
335 #endif
336 	ATTR_LIST(metadata_csum_seed),
337 	ATTR_LIST(fast_commit),
338 #if IS_ENABLED(CONFIG_UNICODE) && defined(CONFIG_FS_ENCRYPTION)
339 	ATTR_LIST(encrypted_casefold),
340 #endif
341 	NULL,
342 };
343 ATTRIBUTE_GROUPS(ext4_feat);
344 
345 static void *calc_ptr(struct ext4_attr *a, struct ext4_sb_info *sbi)
346 {
347 	switch (a->attr_ptr) {
348 	case ptr_explicit:
349 		return a->u.explicit_ptr;
350 	case ptr_ext4_sb_info_offset:
351 		return (void *) (((char *) sbi) + a->u.offset);
352 	case ptr_ext4_super_block_offset:
353 		return (void *) (((char *) sbi->s_es) + a->u.offset);
354 	}
355 	return NULL;
356 }
357 
358 static ssize_t __print_tstamp(char *buf, __le32 lo, __u8 hi)
359 {
360 	return sysfs_emit(buf, "%lld\n",
361 			((time64_t)hi << 32) + le32_to_cpu(lo));
362 }
363 
364 #define print_tstamp(buf, es, tstamp) \
365 	__print_tstamp(buf, (es)->tstamp, (es)->tstamp ## _hi)
366 
367 static ssize_t ext4_attr_show(struct kobject *kobj,
368 			      struct attribute *attr, char *buf)
369 {
370 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
371 						s_kobj);
372 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
373 	void *ptr = calc_ptr(a, sbi);
374 
375 	switch (a->attr_id) {
376 	case attr_delayed_allocation_blocks:
377 		return sysfs_emit(buf, "%llu\n",
378 				(s64) EXT4_C2B(sbi,
379 		       percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
380 	case attr_session_write_kbytes:
381 		return session_write_kbytes_show(sbi, buf);
382 	case attr_lifetime_write_kbytes:
383 		return lifetime_write_kbytes_show(sbi, buf);
384 	case attr_reserved_clusters:
385 		return sysfs_emit(buf, "%llu\n",
386 				(unsigned long long)
387 				atomic64_read(&sbi->s_resv_clusters));
388 	case attr_sra_exceeded_retry_limit:
389 		return sysfs_emit(buf, "%llu\n",
390 				(unsigned long long)
391 			percpu_counter_sum(&sbi->s_sra_exceeded_retry_limit));
392 	case attr_inode_readahead:
393 	case attr_pointer_ui:
394 		if (!ptr)
395 			return 0;
396 		if (a->attr_ptr == ptr_ext4_super_block_offset)
397 			return sysfs_emit(buf, "%u\n",
398 					le32_to_cpup(ptr));
399 		else
400 			return sysfs_emit(buf, "%u\n",
401 					*((unsigned int *) ptr));
402 	case attr_pointer_ul:
403 		if (!ptr)
404 			return 0;
405 		return sysfs_emit(buf, "%lu\n",
406 				*((unsigned long *) ptr));
407 	case attr_pointer_u8:
408 		if (!ptr)
409 			return 0;
410 		return sysfs_emit(buf, "%u\n",
411 				*((unsigned char *) ptr));
412 	case attr_pointer_u64:
413 		if (!ptr)
414 			return 0;
415 		if (a->attr_ptr == ptr_ext4_super_block_offset)
416 			return sysfs_emit(buf, "%llu\n",
417 					le64_to_cpup(ptr));
418 		else
419 			return sysfs_emit(buf, "%llu\n",
420 					*((unsigned long long *) ptr));
421 	case attr_pointer_string:
422 		if (!ptr)
423 			return 0;
424 		return sysfs_emit(buf, "%.*s\n", a->attr_size,
425 				(char *) ptr);
426 	case attr_pointer_atomic:
427 		if (!ptr)
428 			return 0;
429 		return sysfs_emit(buf, "%d\n",
430 				atomic_read((atomic_t *) ptr));
431 	case attr_feature:
432 		return sysfs_emit(buf, "supported\n");
433 	case attr_first_error_time:
434 		return print_tstamp(buf, sbi->s_es, s_first_error_time);
435 	case attr_last_error_time:
436 		return print_tstamp(buf, sbi->s_es, s_last_error_time);
437 	case attr_journal_task:
438 		return journal_task_show(sbi, buf);
439 	}
440 
441 	return 0;
442 }
443 
444 static ssize_t ext4_attr_store(struct kobject *kobj,
445 			       struct attribute *attr,
446 			       const char *buf, size_t len)
447 {
448 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
449 						s_kobj);
450 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
451 	void *ptr = calc_ptr(a, sbi);
452 	unsigned long t;
453 	int ret;
454 
455 	switch (a->attr_id) {
456 	case attr_reserved_clusters:
457 		return reserved_clusters_store(sbi, buf, len);
458 	case attr_pointer_ui:
459 		if (!ptr)
460 			return 0;
461 		ret = kstrtoul(skip_spaces(buf), 0, &t);
462 		if (ret)
463 			return ret;
464 		if (a->attr_ptr == ptr_ext4_super_block_offset)
465 			*((__le32 *) ptr) = cpu_to_le32(t);
466 		else
467 			*((unsigned int *) ptr) = t;
468 		return len;
469 	case attr_pointer_ul:
470 		if (!ptr)
471 			return 0;
472 		ret = kstrtoul(skip_spaces(buf), 0, &t);
473 		if (ret)
474 			return ret;
475 		*((unsigned long *) ptr) = t;
476 		return len;
477 	case attr_inode_readahead:
478 		return inode_readahead_blks_store(sbi, buf, len);
479 	case attr_trigger_test_error:
480 		return trigger_test_error(sbi, buf, len);
481 	}
482 	return 0;
483 }
484 
485 static void ext4_sb_release(struct kobject *kobj)
486 {
487 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
488 						s_kobj);
489 	complete(&sbi->s_kobj_unregister);
490 }
491 
492 static void ext4_feat_release(struct kobject *kobj)
493 {
494 	kfree(kobj);
495 }
496 
497 static const struct sysfs_ops ext4_attr_ops = {
498 	.show	= ext4_attr_show,
499 	.store	= ext4_attr_store,
500 };
501 
502 static const struct kobj_type ext4_sb_ktype = {
503 	.default_groups = ext4_groups,
504 	.sysfs_ops	= &ext4_attr_ops,
505 	.release	= ext4_sb_release,
506 };
507 
508 static const struct kobj_type ext4_feat_ktype = {
509 	.default_groups = ext4_feat_groups,
510 	.sysfs_ops	= &ext4_attr_ops,
511 	.release	= ext4_feat_release,
512 };
513 
514 void ext4_notify_error_sysfs(struct ext4_sb_info *sbi)
515 {
516 	sysfs_notify(&sbi->s_kobj, NULL, "errors_count");
517 }
518 
519 static struct kobject *ext4_root;
520 
521 static struct kobject *ext4_feat;
522 
523 int ext4_register_sysfs(struct super_block *sb)
524 {
525 	struct ext4_sb_info *sbi = EXT4_SB(sb);
526 	int err;
527 
528 	init_completion(&sbi->s_kobj_unregister);
529 	err = kobject_init_and_add(&sbi->s_kobj, &ext4_sb_ktype, ext4_root,
530 				   "%s", sb->s_id);
531 	if (err) {
532 		kobject_put(&sbi->s_kobj);
533 		wait_for_completion(&sbi->s_kobj_unregister);
534 		return err;
535 	}
536 
537 	if (ext4_proc_root)
538 		sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
539 	if (sbi->s_proc) {
540 		proc_create_single_data("options", S_IRUGO, sbi->s_proc,
541 				ext4_seq_options_show, sb);
542 		proc_create_single_data("es_shrinker_info", S_IRUGO,
543 				sbi->s_proc, ext4_seq_es_shrinker_info_show,
544 				sb);
545 		proc_create_single_data("fc_info", 0444, sbi->s_proc,
546 					ext4_fc_info_show, sb);
547 		proc_create_seq_data("mb_groups", S_IRUGO, sbi->s_proc,
548 				&ext4_mb_seq_groups_ops, sb);
549 		proc_create_single_data("mb_stats", 0444, sbi->s_proc,
550 				ext4_seq_mb_stats_show, sb);
551 		proc_create_seq_data("mb_structs_summary", 0444, sbi->s_proc,
552 				&ext4_mb_seq_structs_summary_ops, sb);
553 	}
554 	return 0;
555 }
556 
557 void ext4_unregister_sysfs(struct super_block *sb)
558 {
559 	struct ext4_sb_info *sbi = EXT4_SB(sb);
560 
561 	if (sbi->s_proc)
562 		remove_proc_subtree(sb->s_id, ext4_proc_root);
563 	kobject_del(&sbi->s_kobj);
564 }
565 
566 int __init ext4_init_sysfs(void)
567 {
568 	int ret;
569 
570 	ext4_root = kobject_create_and_add("ext4", fs_kobj);
571 	if (!ext4_root)
572 		return -ENOMEM;
573 
574 	ext4_feat = kzalloc(sizeof(*ext4_feat), GFP_KERNEL);
575 	if (!ext4_feat) {
576 		ret = -ENOMEM;
577 		goto root_err;
578 	}
579 
580 	ret = kobject_init_and_add(ext4_feat, &ext4_feat_ktype,
581 				   ext4_root, "features");
582 	if (ret)
583 		goto feat_err;
584 
585 	ext4_proc_root = proc_mkdir(proc_dirname, NULL);
586 	return ret;
587 
588 feat_err:
589 	kobject_put(ext4_feat);
590 	ext4_feat = NULL;
591 root_err:
592 	kobject_put(ext4_root);
593 	ext4_root = NULL;
594 	return ret;
595 }
596 
597 void ext4_exit_sysfs(void)
598 {
599 	kobject_put(ext4_feat);
600 	ext4_feat = NULL;
601 	kobject_put(ext4_root);
602 	ext4_root = NULL;
603 	remove_proc_entry(proc_dirname, NULL);
604 	ext4_proc_root = NULL;
605 }
606 
607