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