xref: /linux/fs/ext4/sysfs.c (revision 5c2a430e85994f4873ea5ec42091baa1153bc731)
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_mb_order,
34 	attr_feature,
35 	attr_pointer_pi,
36 	attr_pointer_ui,
37 	attr_pointer_ul,
38 	attr_pointer_u64,
39 	attr_pointer_u8,
40 	attr_pointer_string,
41 	attr_pointer_atomic,
42 	attr_journal_task,
43 } attr_id_t;
44 
45 typedef enum {
46 	ptr_explicit,
47 	ptr_ext4_sb_info_offset,
48 	ptr_ext4_super_block_offset,
49 } attr_ptr_t;
50 
51 static const char proc_dirname[] = "fs/ext4";
52 static struct proc_dir_entry *ext4_proc_root;
53 
54 struct ext4_attr {
55 	struct attribute attr;
56 	short attr_id;
57 	short attr_ptr;
58 	unsigned short attr_size;
59 	union {
60 		int offset;
61 		void *explicit_ptr;
62 	} u;
63 };
64 
session_write_kbytes_show(struct ext4_sb_info * sbi,char * buf)65 static ssize_t session_write_kbytes_show(struct ext4_sb_info *sbi, char *buf)
66 {
67 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
68 
69 	return sysfs_emit(buf, "%lu\n",
70 			(part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
71 			 sbi->s_sectors_written_start) >> 1);
72 }
73 
lifetime_write_kbytes_show(struct ext4_sb_info * sbi,char * buf)74 static 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 	return sysfs_emit(buf, "%llu\n",
79 			(unsigned long long)(sbi->s_kbytes_written +
80 			((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
81 			  EXT4_SB(sb)->s_sectors_written_start) >> 1)));
82 }
83 
inode_readahead_blks_store(struct ext4_sb_info * sbi,const char * buf,size_t count)84 static ssize_t inode_readahead_blks_store(struct ext4_sb_info *sbi,
85 					  const char *buf, size_t count)
86 {
87 	unsigned long t;
88 	int ret;
89 
90 	ret = kstrtoul(skip_spaces(buf), 0, &t);
91 	if (ret)
92 		return ret;
93 
94 	if (t && (!is_power_of_2(t) || t > 0x40000000))
95 		return -EINVAL;
96 
97 	sbi->s_inode_readahead_blks = t;
98 	return count;
99 }
100 
reserved_clusters_store(struct ext4_sb_info * sbi,const char * buf,size_t count)101 static ssize_t reserved_clusters_store(struct ext4_sb_info *sbi,
102 				   const char *buf, size_t count)
103 {
104 	unsigned long long val;
105 	ext4_fsblk_t clusters = (ext4_blocks_count(sbi->s_es) >>
106 				 sbi->s_cluster_bits);
107 	int ret;
108 
109 	ret = kstrtoull(skip_spaces(buf), 0, &val);
110 	if (ret || val >= clusters || (s64)val < 0)
111 		return -EINVAL;
112 
113 	atomic64_set(&sbi->s_resv_clusters, val);
114 	return count;
115 }
116 
trigger_test_error(struct ext4_sb_info * sbi,const char * buf,size_t count)117 static ssize_t trigger_test_error(struct ext4_sb_info *sbi,
118 				  const char *buf, size_t count)
119 {
120 	int len = count;
121 
122 	if (!capable(CAP_SYS_ADMIN))
123 		return -EPERM;
124 
125 	if (len && buf[len-1] == '\n')
126 		len--;
127 
128 	if (len)
129 		ext4_error(sbi->s_sb, "%.*s", len, buf);
130 	return count;
131 }
132 
journal_task_show(struct ext4_sb_info * sbi,char * buf)133 static ssize_t journal_task_show(struct ext4_sb_info *sbi, char *buf)
134 {
135 	if (!sbi->s_journal)
136 		return sysfs_emit(buf, "<none>\n");
137 	return sysfs_emit(buf, "%d\n",
138 			task_pid_vnr(sbi->s_journal->j_task));
139 }
140 
141 #define EXT4_ATTR(_name,_mode,_id)					\
142 static struct ext4_attr ext4_attr_##_name = {				\
143 	.attr = {.name = __stringify(_name), .mode = _mode },		\
144 	.attr_id = attr_##_id,						\
145 }
146 
147 #define EXT4_ATTR_FUNC(_name,_mode)  EXT4_ATTR(_name,_mode,_name)
148 
149 #define EXT4_ATTR_FEATURE(_name)   EXT4_ATTR(_name, 0444, feature)
150 
151 #define EXT4_ATTR_OFFSET(_name,_mode,_id,_struct,_elname)	\
152 static struct ext4_attr ext4_attr_##_name = {			\
153 	.attr = {.name = __stringify(_name), .mode = _mode },	\
154 	.attr_id = attr_##_id,					\
155 	.attr_ptr = ptr_##_struct##_offset,			\
156 	.u = {							\
157 		.offset = offsetof(struct _struct, _elname),\
158 	},							\
159 }
160 
161 #define EXT4_ATTR_STRING(_name,_mode,_size,_struct,_elname)	\
162 static struct ext4_attr ext4_attr_##_name = {			\
163 	.attr = {.name = __stringify(_name), .mode = _mode },	\
164 	.attr_id = attr_pointer_string,				\
165 	.attr_size = _size,					\
166 	.attr_ptr = ptr_##_struct##_offset,			\
167 	.u = {							\
168 		.offset = offsetof(struct _struct, _elname),\
169 	},							\
170 }
171 
172 #define EXT4_RO_ATTR_ES_UI(_name,_elname)				\
173 	EXT4_ATTR_OFFSET(_name, 0444, pointer_ui, ext4_super_block, _elname)
174 
175 #define EXT4_RO_ATTR_ES_U8(_name,_elname)				\
176 	EXT4_ATTR_OFFSET(_name, 0444, pointer_u8, ext4_super_block, _elname)
177 
178 #define EXT4_RO_ATTR_ES_U64(_name,_elname)				\
179 	EXT4_ATTR_OFFSET(_name, 0444, pointer_u64, ext4_super_block, _elname)
180 
181 #define EXT4_RO_ATTR_ES_STRING(_name,_elname,_size)			\
182 	EXT4_ATTR_STRING(_name, 0444, _size, ext4_super_block, _elname)
183 
184 #define EXT4_RW_ATTR_SBI_PI(_name,_elname)      \
185 	EXT4_ATTR_OFFSET(_name, 0644, pointer_pi, ext4_sb_info, _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) \
197 static 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 
208 EXT4_ATTR_FUNC(delayed_allocation_blocks, 0444);
209 EXT4_ATTR_FUNC(session_write_kbytes, 0444);
210 EXT4_ATTR_FUNC(lifetime_write_kbytes, 0444);
211 EXT4_ATTR_FUNC(reserved_clusters, 0644);
212 EXT4_ATTR_FUNC(sra_exceeded_retry_limit, 0444);
213 
214 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, inode_readahead,
215 		 ext4_sb_info, s_inode_readahead_blks);
216 EXT4_ATTR_OFFSET(mb_group_prealloc, 0644, clusters_in_group,
217 		 ext4_sb_info, s_mb_group_prealloc);
218 EXT4_ATTR_OFFSET(mb_best_avail_max_trim_order, 0644, mb_order,
219 		 ext4_sb_info, s_mb_best_avail_max_trim_order);
220 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
221 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
222 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
223 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
224 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
225 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
226 EXT4_RW_ATTR_SBI_UI(mb_max_linear_groups, s_mb_max_linear_groups);
227 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
228 EXT4_ATTR(trigger_fs_error, 0200, trigger_test_error);
229 EXT4_RW_ATTR_SBI_PI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);
230 EXT4_RW_ATTR_SBI_PI(err_ratelimit_burst, s_err_ratelimit_state.burst);
231 EXT4_RW_ATTR_SBI_PI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);
232 EXT4_RW_ATTR_SBI_PI(warning_ratelimit_burst, s_warning_ratelimit_state.burst);
233 EXT4_RW_ATTR_SBI_PI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval);
234 EXT4_RW_ATTR_SBI_PI(msg_ratelimit_burst, s_msg_ratelimit_state.burst);
235 #ifdef CONFIG_EXT4_DEBUG
236 EXT4_RW_ATTR_SBI_UL(simulate_fail, s_simulate_fail);
237 #endif
238 EXT4_RO_ATTR_SBI_ATOMIC(warning_count, s_warning_count);
239 EXT4_RO_ATTR_SBI_ATOMIC(msg_count, s_msg_count);
240 EXT4_RO_ATTR_ES_UI(errors_count, s_error_count);
241 EXT4_RO_ATTR_ES_U8(first_error_errcode, s_first_error_errcode);
242 EXT4_RO_ATTR_ES_U8(last_error_errcode, s_last_error_errcode);
243 EXT4_RO_ATTR_ES_UI(first_error_ino, s_first_error_ino);
244 EXT4_RO_ATTR_ES_UI(last_error_ino, s_last_error_ino);
245 EXT4_RO_ATTR_ES_U64(first_error_block, s_first_error_block);
246 EXT4_RO_ATTR_ES_U64(last_error_block, s_last_error_block);
247 EXT4_RO_ATTR_ES_UI(first_error_line, s_first_error_line);
248 EXT4_RO_ATTR_ES_UI(last_error_line, s_last_error_line);
249 EXT4_RO_ATTR_ES_STRING(first_error_func, s_first_error_func, 32);
250 EXT4_RO_ATTR_ES_STRING(last_error_func, s_last_error_func, 32);
251 EXT4_ATTR(first_error_time, 0444, first_error_time);
252 EXT4_ATTR(last_error_time, 0444, last_error_time);
253 EXT4_ATTR(journal_task, 0444, journal_task);
254 EXT4_RW_ATTR_SBI_UI(mb_prefetch, s_mb_prefetch);
255 EXT4_RW_ATTR_SBI_UI(mb_prefetch_limit, s_mb_prefetch_limit);
256 EXT4_RW_ATTR_SBI_UL(last_trim_minblks, s_last_trim_minblks);
257 EXT4_RW_ATTR_SBI_UI(sb_update_sec, s_sb_update_sec);
258 EXT4_RW_ATTR_SBI_UI(sb_update_kb, s_sb_update_kb);
259 
260 static unsigned int old_bump_val = 128;
261 EXT4_ATTR_PTR(max_writeback_mb_bump, 0444, pointer_ui, &old_bump_val);
262 
263 static struct attribute *ext4_attrs[] = {
264 	ATTR_LIST(delayed_allocation_blocks),
265 	ATTR_LIST(session_write_kbytes),
266 	ATTR_LIST(lifetime_write_kbytes),
267 	ATTR_LIST(reserved_clusters),
268 	ATTR_LIST(sra_exceeded_retry_limit),
269 	ATTR_LIST(inode_readahead_blks),
270 	ATTR_LIST(inode_goal),
271 	ATTR_LIST(mb_stats),
272 	ATTR_LIST(mb_max_to_scan),
273 	ATTR_LIST(mb_min_to_scan),
274 	ATTR_LIST(mb_order2_req),
275 	ATTR_LIST(mb_stream_req),
276 	ATTR_LIST(mb_group_prealloc),
277 	ATTR_LIST(mb_max_linear_groups),
278 	ATTR_LIST(max_writeback_mb_bump),
279 	ATTR_LIST(extent_max_zeroout_kb),
280 	ATTR_LIST(trigger_fs_error),
281 	ATTR_LIST(err_ratelimit_interval_ms),
282 	ATTR_LIST(err_ratelimit_burst),
283 	ATTR_LIST(warning_ratelimit_interval_ms),
284 	ATTR_LIST(warning_ratelimit_burst),
285 	ATTR_LIST(msg_ratelimit_interval_ms),
286 	ATTR_LIST(msg_ratelimit_burst),
287 	ATTR_LIST(mb_best_avail_max_trim_order),
288 	ATTR_LIST(errors_count),
289 	ATTR_LIST(warning_count),
290 	ATTR_LIST(msg_count),
291 	ATTR_LIST(first_error_ino),
292 	ATTR_LIST(last_error_ino),
293 	ATTR_LIST(first_error_block),
294 	ATTR_LIST(last_error_block),
295 	ATTR_LIST(first_error_line),
296 	ATTR_LIST(last_error_line),
297 	ATTR_LIST(first_error_func),
298 	ATTR_LIST(last_error_func),
299 	ATTR_LIST(first_error_errcode),
300 	ATTR_LIST(last_error_errcode),
301 	ATTR_LIST(first_error_time),
302 	ATTR_LIST(last_error_time),
303 	ATTR_LIST(journal_task),
304 #ifdef CONFIG_EXT4_DEBUG
305 	ATTR_LIST(simulate_fail),
306 #endif
307 	ATTR_LIST(mb_prefetch),
308 	ATTR_LIST(mb_prefetch_limit),
309 	ATTR_LIST(last_trim_minblks),
310 	ATTR_LIST(sb_update_sec),
311 	ATTR_LIST(sb_update_kb),
312 	NULL,
313 };
314 ATTRIBUTE_GROUPS(ext4);
315 
316 /* Features this copy of ext4 supports */
317 EXT4_ATTR_FEATURE(lazy_itable_init);
318 EXT4_ATTR_FEATURE(batched_discard);
319 EXT4_ATTR_FEATURE(meta_bg_resize);
320 #ifdef CONFIG_FS_ENCRYPTION
321 EXT4_ATTR_FEATURE(encryption);
322 EXT4_ATTR_FEATURE(test_dummy_encryption_v2);
323 #endif
324 #if IS_ENABLED(CONFIG_UNICODE)
325 EXT4_ATTR_FEATURE(casefold);
326 #endif
327 #ifdef CONFIG_FS_VERITY
328 EXT4_ATTR_FEATURE(verity);
329 #endif
330 EXT4_ATTR_FEATURE(metadata_csum_seed);
331 EXT4_ATTR_FEATURE(fast_commit);
332 #if IS_ENABLED(CONFIG_UNICODE) && defined(CONFIG_FS_ENCRYPTION)
333 EXT4_ATTR_FEATURE(encrypted_casefold);
334 #endif
335 
336 static struct attribute *ext4_feat_attrs[] = {
337 	ATTR_LIST(lazy_itable_init),
338 	ATTR_LIST(batched_discard),
339 	ATTR_LIST(meta_bg_resize),
340 #ifdef CONFIG_FS_ENCRYPTION
341 	ATTR_LIST(encryption),
342 	ATTR_LIST(test_dummy_encryption_v2),
343 #endif
344 #if IS_ENABLED(CONFIG_UNICODE)
345 	ATTR_LIST(casefold),
346 #endif
347 #ifdef CONFIG_FS_VERITY
348 	ATTR_LIST(verity),
349 #endif
350 	ATTR_LIST(metadata_csum_seed),
351 	ATTR_LIST(fast_commit),
352 #if IS_ENABLED(CONFIG_UNICODE) && defined(CONFIG_FS_ENCRYPTION)
353 	ATTR_LIST(encrypted_casefold),
354 #endif
355 	NULL,
356 };
357 ATTRIBUTE_GROUPS(ext4_feat);
358 
calc_ptr(struct ext4_attr * a,struct ext4_sb_info * sbi)359 static void *calc_ptr(struct ext4_attr *a, struct ext4_sb_info *sbi)
360 {
361 	switch (a->attr_ptr) {
362 	case ptr_explicit:
363 		return a->u.explicit_ptr;
364 	case ptr_ext4_sb_info_offset:
365 		return (void *) (((char *) sbi) + a->u.offset);
366 	case ptr_ext4_super_block_offset:
367 		return (void *) (((char *) sbi->s_es) + a->u.offset);
368 	}
369 	return NULL;
370 }
371 
__print_tstamp(char * buf,__le32 lo,__u8 hi)372 static ssize_t __print_tstamp(char *buf, __le32 lo, __u8 hi)
373 {
374 	return sysfs_emit(buf, "%lld\n",
375 			((time64_t)hi << 32) + le32_to_cpu(lo));
376 }
377 
378 #define print_tstamp(buf, es, tstamp) \
379 	__print_tstamp(buf, (es)->tstamp, (es)->tstamp ## _hi)
380 
ext4_generic_attr_show(struct ext4_attr * a,struct ext4_sb_info * sbi,char * buf)381 static ssize_t ext4_generic_attr_show(struct ext4_attr *a,
382 				      struct ext4_sb_info *sbi, char *buf)
383 {
384 	void *ptr = calc_ptr(a, sbi);
385 
386 	if (!ptr)
387 		return 0;
388 
389 	switch (a->attr_id) {
390 	case attr_inode_readahead:
391 	case attr_clusters_in_group:
392 	case attr_mb_order:
393 	case attr_pointer_pi:
394 	case attr_pointer_ui:
395 		if (a->attr_ptr == ptr_ext4_super_block_offset)
396 			return sysfs_emit(buf, "%u\n", le32_to_cpup(ptr));
397 		return sysfs_emit(buf, "%u\n", *((unsigned int *) ptr));
398 	case attr_pointer_ul:
399 		return sysfs_emit(buf, "%lu\n", *((unsigned long *) ptr));
400 	case attr_pointer_u8:
401 		return sysfs_emit(buf, "%u\n", *((unsigned char *) ptr));
402 	case attr_pointer_u64:
403 		if (a->attr_ptr == ptr_ext4_super_block_offset)
404 			return sysfs_emit(buf, "%llu\n", le64_to_cpup(ptr));
405 		return sysfs_emit(buf, "%llu\n", *((unsigned long long *) ptr));
406 	case attr_pointer_string:
407 		return sysfs_emit(buf, "%.*s\n", a->attr_size, (char *) ptr);
408 	case attr_pointer_atomic:
409 		return sysfs_emit(buf, "%d\n", atomic_read((atomic_t *) ptr));
410 	}
411 	return 0;
412 }
413 
ext4_attr_show(struct kobject * kobj,struct attribute * attr,char * buf)414 static ssize_t ext4_attr_show(struct kobject *kobj,
415 			      struct attribute *attr, char *buf)
416 {
417 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
418 						s_kobj);
419 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
420 
421 	switch (a->attr_id) {
422 	case attr_delayed_allocation_blocks:
423 		return sysfs_emit(buf, "%llu\n",
424 				(s64) EXT4_C2B(sbi,
425 		       percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
426 	case attr_session_write_kbytes:
427 		return session_write_kbytes_show(sbi, buf);
428 	case attr_lifetime_write_kbytes:
429 		return lifetime_write_kbytes_show(sbi, buf);
430 	case attr_reserved_clusters:
431 		return sysfs_emit(buf, "%llu\n",
432 				(unsigned long long)
433 				atomic64_read(&sbi->s_resv_clusters));
434 	case attr_sra_exceeded_retry_limit:
435 		return sysfs_emit(buf, "%llu\n",
436 				(unsigned long long)
437 			percpu_counter_sum(&sbi->s_sra_exceeded_retry_limit));
438 	case attr_feature:
439 		return sysfs_emit(buf, "supported\n");
440 	case attr_first_error_time:
441 		return print_tstamp(buf, sbi->s_es, s_first_error_time);
442 	case attr_last_error_time:
443 		return print_tstamp(buf, sbi->s_es, s_last_error_time);
444 	case attr_journal_task:
445 		return journal_task_show(sbi, buf);
446 	default:
447 		return ext4_generic_attr_show(a, sbi, buf);
448 	}
449 }
450 
ext4_generic_attr_store(struct ext4_attr * a,struct ext4_sb_info * sbi,const char * buf,size_t len)451 static ssize_t ext4_generic_attr_store(struct ext4_attr *a,
452 				       struct ext4_sb_info *sbi,
453 				       const char *buf, size_t len)
454 {
455 	int ret;
456 	unsigned int t;
457 	unsigned long lt;
458 	void *ptr = calc_ptr(a, sbi);
459 
460 	if (!ptr)
461 		return 0;
462 
463 	switch (a->attr_id) {
464 	case attr_pointer_pi:
465 		ret = kstrtouint(skip_spaces(buf), 0, &t);
466 		if (ret)
467 			return ret;
468 		if ((int)t < 0)
469 			return -EINVAL;
470 		*((unsigned int *) ptr) = t;
471 		return len;
472 	case attr_pointer_ui:
473 		ret = kstrtouint(skip_spaces(buf), 0, &t);
474 		if (ret)
475 			return ret;
476 		if (a->attr_ptr == ptr_ext4_super_block_offset)
477 			*((__le32 *) ptr) = cpu_to_le32(t);
478 		else
479 			*((unsigned int *) ptr) = t;
480 		return len;
481 	case attr_mb_order:
482 		ret = kstrtouint(skip_spaces(buf), 0, &t);
483 		if (ret)
484 			return ret;
485 		if (t > 64)
486 			return -EINVAL;
487 		*((unsigned int *) ptr) = t;
488 		return len;
489 	case attr_clusters_in_group:
490 		ret = kstrtouint(skip_spaces(buf), 0, &t);
491 		if (ret)
492 			return ret;
493 		if (t > sbi->s_clusters_per_group)
494 			return -EINVAL;
495 		*((unsigned int *) ptr) = t;
496 		return len;
497 	case attr_pointer_ul:
498 		ret = kstrtoul(skip_spaces(buf), 0, &lt);
499 		if (ret)
500 			return ret;
501 		*((unsigned long *) ptr) = lt;
502 		return len;
503 	}
504 	return 0;
505 }
506 
ext4_attr_store(struct kobject * kobj,struct attribute * attr,const char * buf,size_t len)507 static ssize_t ext4_attr_store(struct kobject *kobj,
508 			       struct attribute *attr,
509 			       const char *buf, size_t len)
510 {
511 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
512 						s_kobj);
513 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
514 
515 	switch (a->attr_id) {
516 	case attr_reserved_clusters:
517 		return reserved_clusters_store(sbi, buf, len);
518 	case attr_inode_readahead:
519 		return inode_readahead_blks_store(sbi, buf, len);
520 	case attr_trigger_test_error:
521 		return trigger_test_error(sbi, buf, len);
522 	default:
523 		return ext4_generic_attr_store(a, sbi, buf, len);
524 	}
525 }
526 
ext4_sb_release(struct kobject * kobj)527 static void ext4_sb_release(struct kobject *kobj)
528 {
529 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
530 						s_kobj);
531 	complete(&sbi->s_kobj_unregister);
532 }
533 
ext4_feat_release(struct kobject * kobj)534 static void ext4_feat_release(struct kobject *kobj)
535 {
536 	kfree(kobj);
537 }
538 
539 static const struct sysfs_ops ext4_attr_ops = {
540 	.show	= ext4_attr_show,
541 	.store	= ext4_attr_store,
542 };
543 
544 static const struct kobj_type ext4_sb_ktype = {
545 	.default_groups = ext4_groups,
546 	.sysfs_ops	= &ext4_attr_ops,
547 	.release	= ext4_sb_release,
548 };
549 
550 static const struct kobj_type ext4_feat_ktype = {
551 	.default_groups = ext4_feat_groups,
552 	.sysfs_ops	= &ext4_attr_ops,
553 	.release	= ext4_feat_release,
554 };
555 
ext4_notify_error_sysfs(struct ext4_sb_info * sbi)556 void ext4_notify_error_sysfs(struct ext4_sb_info *sbi)
557 {
558 	sysfs_notify(&sbi->s_kobj, NULL, "errors_count");
559 }
560 
561 static struct kobject *ext4_root;
562 
563 static struct kobject *ext4_feat;
564 
ext4_register_sysfs(struct super_block * sb)565 int ext4_register_sysfs(struct super_block *sb)
566 {
567 	struct ext4_sb_info *sbi = EXT4_SB(sb);
568 	int err;
569 
570 	init_completion(&sbi->s_kobj_unregister);
571 	err = kobject_init_and_add(&sbi->s_kobj, &ext4_sb_ktype, ext4_root,
572 				   "%s", sb->s_id);
573 	if (err) {
574 		kobject_put(&sbi->s_kobj);
575 		wait_for_completion(&sbi->s_kobj_unregister);
576 		return err;
577 	}
578 
579 	if (ext4_proc_root)
580 		sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
581 	if (sbi->s_proc) {
582 		proc_create_single_data("options", S_IRUGO, sbi->s_proc,
583 				ext4_seq_options_show, sb);
584 		proc_create_single_data("es_shrinker_info", S_IRUGO,
585 				sbi->s_proc, ext4_seq_es_shrinker_info_show,
586 				sb);
587 		proc_create_single_data("fc_info", 0444, sbi->s_proc,
588 					ext4_fc_info_show, sb);
589 		proc_create_seq_data("mb_groups", S_IRUGO, sbi->s_proc,
590 				&ext4_mb_seq_groups_ops, sb);
591 		proc_create_single_data("mb_stats", 0444, sbi->s_proc,
592 				ext4_seq_mb_stats_show, sb);
593 		proc_create_seq_data("mb_structs_summary", 0444, sbi->s_proc,
594 				&ext4_mb_seq_structs_summary_ops, sb);
595 	}
596 	return 0;
597 }
598 
ext4_unregister_sysfs(struct super_block * sb)599 void ext4_unregister_sysfs(struct super_block *sb)
600 {
601 	struct ext4_sb_info *sbi = EXT4_SB(sb);
602 
603 	if (sbi->s_proc)
604 		remove_proc_subtree(sb->s_id, ext4_proc_root);
605 	kobject_del(&sbi->s_kobj);
606 }
607 
ext4_init_sysfs(void)608 int __init ext4_init_sysfs(void)
609 {
610 	int ret;
611 
612 	ext4_root = kobject_create_and_add("ext4", fs_kobj);
613 	if (!ext4_root)
614 		return -ENOMEM;
615 
616 	ext4_feat = kzalloc(sizeof(*ext4_feat), GFP_KERNEL);
617 	if (!ext4_feat) {
618 		ret = -ENOMEM;
619 		goto root_err;
620 	}
621 
622 	ret = kobject_init_and_add(ext4_feat, &ext4_feat_ktype,
623 				   ext4_root, "features");
624 	if (ret)
625 		goto feat_err;
626 
627 	ext4_proc_root = proc_mkdir(proc_dirname, NULL);
628 	return ret;
629 
630 feat_err:
631 	kobject_put(ext4_feat);
632 	ext4_feat = NULL;
633 root_err:
634 	kobject_put(ext4_root);
635 	ext4_root = NULL;
636 	return ret;
637 }
638 
ext4_exit_sysfs(void)639 void ext4_exit_sysfs(void)
640 {
641 	kobject_put(ext4_feat);
642 	ext4_feat = NULL;
643 	kobject_put(ext4_root);
644 	ext4_root = NULL;
645 	remove_proc_entry(proc_dirname, NULL);
646 	ext4_proc_root = NULL;
647 }
648 
649