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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
17#include "ext4.h"
18#include "ext4_jbd2.h"
19
20typedef enum {
21 attr_noop,
22 attr_delayed_allocation_blocks,
23 attr_session_write_kbytes,
24 attr_lifetime_write_kbytes,
25 attr_reserved_clusters,
26 attr_inode_readahead,
27 attr_trigger_test_error,
28 attr_first_error_time,
29 attr_last_error_time,
30 attr_feature,
31 attr_pointer_ui,
32 attr_pointer_atomic,
33 attr_journal_task,
34} attr_id_t;
35
36typedef enum {
37 ptr_explicit,
38 ptr_ext4_sb_info_offset,
39 ptr_ext4_super_block_offset,
40} attr_ptr_t;
41
42static const char proc_dirname[] = "fs/ext4";
43static struct proc_dir_entry *ext4_proc_root;
44
45struct ext4_attr {
46 struct attribute attr;
47 short attr_id;
48 short attr_ptr;
49 union {
50 int offset;
51 void *explicit_ptr;
52 } u;
53};
54
55static ssize_t session_write_kbytes_show(struct ext4_sb_info *sbi, char *buf)
56{
57 struct super_block *sb = sbi->s_buddy_cache->i_sb;
58
59 if (!sb->s_bdev->bd_part)
60 return snprintf(buf, PAGE_SIZE, "0\n");
61 return snprintf(buf, PAGE_SIZE, "%lu\n",
62 (part_stat_read(sb->s_bdev->bd_part,
63 sectors[STAT_WRITE]) -
64 sbi->s_sectors_written_start) >> 1);
65}
66
67static ssize_t lifetime_write_kbytes_show(struct ext4_sb_info *sbi, char *buf)
68{
69 struct super_block *sb = sbi->s_buddy_cache->i_sb;
70
71 if (!sb->s_bdev->bd_part)
72 return snprintf(buf, PAGE_SIZE, "0\n");
73 return snprintf(buf, PAGE_SIZE, "%llu\n",
74 (unsigned long long)(sbi->s_kbytes_written +
75 ((part_stat_read(sb->s_bdev->bd_part,
76 sectors[STAT_WRITE]) -
77 EXT4_SB(sb)->s_sectors_written_start) >> 1)));
78}
79
80static ssize_t inode_readahead_blks_store(struct ext4_sb_info *sbi,
81 const char *buf, size_t count)
82{
83 unsigned long t;
84 int ret;
85
86 ret = kstrtoul(skip_spaces(buf), 0, &t);
87 if (ret)
88 return ret;
89
90 if (t && (!is_power_of_2(t) || t > 0x40000000))
91 return -EINVAL;
92
93 sbi->s_inode_readahead_blks = t;
94 return count;
95}
96
97static ssize_t reserved_clusters_store(struct ext4_sb_info *sbi,
98 const char *buf, size_t count)
99{
100 unsigned long long val;
101 ext4_fsblk_t clusters = (ext4_blocks_count(sbi->s_es) >>
102 sbi->s_cluster_bits);
103 int ret;
104
105 ret = kstrtoull(skip_spaces(buf), 0, &val);
106 if (ret || val >= clusters)
107 return -EINVAL;
108
109 atomic64_set(&sbi->s_resv_clusters, val);
110 return count;
111}
112
113static ssize_t trigger_test_error(struct ext4_sb_info *sbi,
114 const char *buf, size_t count)
115{
116 int len = count;
117
118 if (!capable(CAP_SYS_ADMIN))
119 return -EPERM;
120
121 if (len && buf[len-1] == '\n')
122 len--;
123
124 if (len)
125 ext4_error(sbi->s_sb, "%.*s", len, buf);
126 return count;
127}
128
129static ssize_t journal_task_show(struct ext4_sb_info *sbi, char *buf)
130{
131 if (!sbi->s_journal)
132 return snprintf(buf, PAGE_SIZE, "<none>\n");
133 return snprintf(buf, PAGE_SIZE, "%d\n",
134 task_pid_vnr(sbi->s_journal->j_task));
135}
136
137#define EXT4_ATTR(_name,_mode,_id) \
138static struct ext4_attr ext4_attr_##_name = { \
139 .attr = {.name = __stringify(_name), .mode = _mode }, \
140 .attr_id = attr_##_id, \
141}
142
143#define EXT4_ATTR_FUNC(_name,_mode) EXT4_ATTR(_name,_mode,_name)
144
145#define EXT4_ATTR_FEATURE(_name) EXT4_ATTR(_name, 0444, feature)
146
147#define EXT4_ATTR_OFFSET(_name,_mode,_id,_struct,_elname) \
148static struct ext4_attr ext4_attr_##_name = { \
149 .attr = {.name = __stringify(_name), .mode = _mode }, \
150 .attr_id = attr_##_id, \
151 .attr_ptr = ptr_##_struct##_offset, \
152 .u = { \
153 .offset = offsetof(struct _struct, _elname),\
154 }, \
155}
156
157#define EXT4_RO_ATTR_ES_UI(_name,_elname) \
158 EXT4_ATTR_OFFSET(_name, 0444, pointer_ui, ext4_super_block, _elname)
159
160#define EXT4_RW_ATTR_SBI_UI(_name,_elname) \
161 EXT4_ATTR_OFFSET(_name, 0644, pointer_ui, ext4_sb_info, _elname)
162
163#define EXT4_ATTR_PTR(_name,_mode,_id,_ptr) \
164static struct ext4_attr ext4_attr_##_name = { \
165 .attr = {.name = __stringify(_name), .mode = _mode }, \
166 .attr_id = attr_##_id, \
167 .attr_ptr = ptr_explicit, \
168 .u = { \
169 .explicit_ptr = _ptr, \
170 }, \
171}
172
173#define ATTR_LIST(name) &ext4_attr_##name.attr
174
175EXT4_ATTR_FUNC(delayed_allocation_blocks, 0444);
176EXT4_ATTR_FUNC(session_write_kbytes, 0444);
177EXT4_ATTR_FUNC(lifetime_write_kbytes, 0444);
178EXT4_ATTR_FUNC(reserved_clusters, 0644);
179
180EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, inode_readahead,
181 ext4_sb_info, s_inode_readahead_blks);
182EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
183EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
184EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
185EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
186EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
187EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
188EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
189EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
190EXT4_ATTR(trigger_fs_error, 0200, trigger_test_error);
191EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);
192EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst);
193EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);
194EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst);
195EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval);
196EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst);
197EXT4_RO_ATTR_ES_UI(errors_count, s_error_count);
198EXT4_ATTR(first_error_time, 0444, first_error_time);
199EXT4_ATTR(last_error_time, 0444, last_error_time);
200EXT4_ATTR(journal_task, 0444, journal_task);
201
202static unsigned int old_bump_val = 128;
203EXT4_ATTR_PTR(max_writeback_mb_bump, 0444, pointer_ui, &old_bump_val);
204
205static struct attribute *ext4_attrs[] = {
206 ATTR_LIST(delayed_allocation_blocks),
207 ATTR_LIST(session_write_kbytes),
208 ATTR_LIST(lifetime_write_kbytes),
209 ATTR_LIST(reserved_clusters),
210 ATTR_LIST(inode_readahead_blks),
211 ATTR_LIST(inode_goal),
212 ATTR_LIST(mb_stats),
213 ATTR_LIST(mb_max_to_scan),
214 ATTR_LIST(mb_min_to_scan),
215 ATTR_LIST(mb_order2_req),
216 ATTR_LIST(mb_stream_req),
217 ATTR_LIST(mb_group_prealloc),
218 ATTR_LIST(max_writeback_mb_bump),
219 ATTR_LIST(extent_max_zeroout_kb),
220 ATTR_LIST(trigger_fs_error),
221 ATTR_LIST(err_ratelimit_interval_ms),
222 ATTR_LIST(err_ratelimit_burst),
223 ATTR_LIST(warning_ratelimit_interval_ms),
224 ATTR_LIST(warning_ratelimit_burst),
225 ATTR_LIST(msg_ratelimit_interval_ms),
226 ATTR_LIST(msg_ratelimit_burst),
227 ATTR_LIST(errors_count),
228 ATTR_LIST(first_error_time),
229 ATTR_LIST(last_error_time),
230 ATTR_LIST(journal_task),
231 NULL,
232};
233ATTRIBUTE_GROUPS(ext4);
234
235/* Features this copy of ext4 supports */
236EXT4_ATTR_FEATURE(lazy_itable_init);
237EXT4_ATTR_FEATURE(batched_discard);
238EXT4_ATTR_FEATURE(meta_bg_resize);
239#ifdef CONFIG_FS_ENCRYPTION
240EXT4_ATTR_FEATURE(encryption);
241#endif
242#ifdef CONFIG_UNICODE
243EXT4_ATTR_FEATURE(casefold);
244#endif
245#ifdef CONFIG_FS_VERITY
246EXT4_ATTR_FEATURE(verity);
247#endif
248EXT4_ATTR_FEATURE(metadata_csum_seed);
249
250static struct attribute *ext4_feat_attrs[] = {
251 ATTR_LIST(lazy_itable_init),
252 ATTR_LIST(batched_discard),
253 ATTR_LIST(meta_bg_resize),
254#ifdef CONFIG_FS_ENCRYPTION
255 ATTR_LIST(encryption),
256#endif
257#ifdef CONFIG_UNICODE
258 ATTR_LIST(casefold),
259#endif
260#ifdef CONFIG_FS_VERITY
261 ATTR_LIST(verity),
262#endif
263 ATTR_LIST(metadata_csum_seed),
264 NULL,
265};
266ATTRIBUTE_GROUPS(ext4_feat);
267
268static void *calc_ptr(struct ext4_attr *a, struct ext4_sb_info *sbi)
269{
270 switch (a->attr_ptr) {
271 case ptr_explicit:
272 return a->u.explicit_ptr;
273 case ptr_ext4_sb_info_offset:
274 return (void *) (((char *) sbi) + a->u.offset);
275 case ptr_ext4_super_block_offset:
276 return (void *) (((char *) sbi->s_es) + a->u.offset);
277 }
278 return NULL;
279}
280
281static ssize_t __print_tstamp(char *buf, __le32 lo, __u8 hi)
282{
283 return snprintf(buf, PAGE_SIZE, "%lld",
284 ((time64_t)hi << 32) + le32_to_cpu(lo));
285}
286
287#define print_tstamp(buf, es, tstamp) \
288 __print_tstamp(buf, (es)->tstamp, (es)->tstamp ## _hi)
289
290static ssize_t ext4_attr_show(struct kobject *kobj,
291 struct attribute *attr, char *buf)
292{
293 struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
294 s_kobj);
295 struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
296 void *ptr = calc_ptr(a, sbi);
297
298 switch (a->attr_id) {
299 case attr_delayed_allocation_blocks:
300 return snprintf(buf, PAGE_SIZE, "%llu\n",
301 (s64) EXT4_C2B(sbi,
302 percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
303 case attr_session_write_kbytes:
304 return session_write_kbytes_show(sbi, buf);
305 case attr_lifetime_write_kbytes:
306 return lifetime_write_kbytes_show(sbi, buf);
307 case attr_reserved_clusters:
308 return snprintf(buf, PAGE_SIZE, "%llu\n",
309 (unsigned long long)
310 atomic64_read(&sbi->s_resv_clusters));
311 case attr_inode_readahead:
312 case attr_pointer_ui:
313 if (!ptr)
314 return 0;
315 if (a->attr_ptr == ptr_ext4_super_block_offset)
316 return snprintf(buf, PAGE_SIZE, "%u\n",
317 le32_to_cpup(ptr));
318 else
319 return snprintf(buf, PAGE_SIZE, "%u\n",
320 *((unsigned int *) ptr));
321 case attr_pointer_atomic:
322 if (!ptr)
323 return 0;
324 return snprintf(buf, PAGE_SIZE, "%d\n",
325 atomic_read((atomic_t *) ptr));
326 case attr_feature:
327 return snprintf(buf, PAGE_SIZE, "supported\n");
328 case attr_first_error_time:
329 return print_tstamp(buf, sbi->s_es, s_first_error_time);
330 case attr_last_error_time:
331 return print_tstamp(buf, sbi->s_es, s_last_error_time);
332 case attr_journal_task:
333 return journal_task_show(sbi, buf);
334 }
335
336 return 0;
337}
338
339static ssize_t ext4_attr_store(struct kobject *kobj,
340 struct attribute *attr,
341 const char *buf, size_t len)
342{
343 struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
344 s_kobj);
345 struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
346 void *ptr = calc_ptr(a, sbi);
347 unsigned long t;
348 int ret;
349
350 switch (a->attr_id) {
351 case attr_reserved_clusters:
352 return reserved_clusters_store(sbi, buf, len);
353 case attr_pointer_ui:
354 if (!ptr)
355 return 0;
356 ret = kstrtoul(skip_spaces(buf), 0, &t);
357 if (ret)
358 return ret;
359 if (a->attr_ptr == ptr_ext4_super_block_offset)
360 *((__le32 *) ptr) = cpu_to_le32(t);
361 else
362 *((unsigned int *) ptr) = t;
363 return len;
364 case attr_inode_readahead:
365 return inode_readahead_blks_store(sbi, buf, len);
366 case attr_trigger_test_error:
367 return trigger_test_error(sbi, buf, len);
368 }
369 return 0;
370}
371
372static void ext4_sb_release(struct kobject *kobj)
373{
374 struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
375 s_kobj);
376 complete(&sbi->s_kobj_unregister);
377}
378
379static const struct sysfs_ops ext4_attr_ops = {
380 .show = ext4_attr_show,
381 .store = ext4_attr_store,
382};
383
384static struct kobj_type ext4_sb_ktype = {
385 .default_groups = ext4_groups,
386 .sysfs_ops = &ext4_attr_ops,
387 .release = ext4_sb_release,
388};
389
390static struct kobj_type ext4_feat_ktype = {
391 .default_groups = ext4_feat_groups,
392 .sysfs_ops = &ext4_attr_ops,
393 .release = (void (*)(struct kobject *))kfree,
394};
395
396static struct kobject *ext4_root;
397
398static struct kobject *ext4_feat;
399
400int ext4_register_sysfs(struct super_block *sb)
401{
402 struct ext4_sb_info *sbi = EXT4_SB(sb);
403 int err;
404
405 init_completion(&sbi->s_kobj_unregister);
406 err = kobject_init_and_add(&sbi->s_kobj, &ext4_sb_ktype, ext4_root,
407 "%s", sb->s_id);
408 if (err) {
409 kobject_put(&sbi->s_kobj);
410 wait_for_completion(&sbi->s_kobj_unregister);
411 return err;
412 }
413
414 if (ext4_proc_root)
415 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
416 if (sbi->s_proc) {
417 proc_create_single_data("options", S_IRUGO, sbi->s_proc,
418 ext4_seq_options_show, sb);
419 proc_create_single_data("es_shrinker_info", S_IRUGO,
420 sbi->s_proc, ext4_seq_es_shrinker_info_show,
421 sb);
422 proc_create_seq_data("mb_groups", S_IRUGO, sbi->s_proc,
423 &ext4_mb_seq_groups_ops, sb);
424 }
425 return 0;
426}
427
428void ext4_unregister_sysfs(struct super_block *sb)
429{
430 struct ext4_sb_info *sbi = EXT4_SB(sb);
431
432 if (sbi->s_proc)
433 remove_proc_subtree(sb->s_id, ext4_proc_root);
434 kobject_del(&sbi->s_kobj);
435}
436
437int __init ext4_init_sysfs(void)
438{
439 int ret;
440
441 ext4_root = kobject_create_and_add("ext4", fs_kobj);
442 if (!ext4_root)
443 return -ENOMEM;
444
445 ext4_feat = kzalloc(sizeof(*ext4_feat), GFP_KERNEL);
446 if (!ext4_feat) {
447 ret = -ENOMEM;
448 goto root_err;
449 }
450
451 ret = kobject_init_and_add(ext4_feat, &ext4_feat_ktype,
452 ext4_root, "features");
453 if (ret)
454 goto feat_err;
455
456 ext4_proc_root = proc_mkdir(proc_dirname, NULL);
457 return ret;
458
459feat_err:
460 kobject_put(ext4_feat);
461 ext4_feat = NULL;
462root_err:
463 kobject_put(ext4_root);
464 ext4_root = NULL;
465 return ret;
466}
467
468void ext4_exit_sysfs(void)
469{
470 kobject_put(ext4_feat);
471 ext4_feat = NULL;
472 kobject_put(ext4_root);
473 ext4_root = NULL;
474 remove_proc_entry(proc_dirname, NULL);
475 ext4_proc_root = NULL;
476}
477