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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_feature,
29 attr_pointer_ui,
30 attr_pointer_atomic,
31} attr_id_t;
32
33typedef enum {
34 ptr_explicit,
35 ptr_ext4_sb_info_offset,
36 ptr_ext4_super_block_offset,
37} attr_ptr_t;
38
39static const char proc_dirname[] = "fs/ext4";
40static struct proc_dir_entry *ext4_proc_root;
41
42struct ext4_attr {
43 struct attribute attr;
44 short attr_id;
45 short attr_ptr;
46 union {
47 int offset;
48 void *explicit_ptr;
49 } u;
50};
51
52static ssize_t session_write_kbytes_show(struct ext4_sb_info *sbi, char *buf)
53{
54 struct super_block *sb = sbi->s_buddy_cache->i_sb;
55
56 if (!sb->s_bdev->bd_part)
57 return snprintf(buf, PAGE_SIZE, "0\n");
58 return snprintf(buf, PAGE_SIZE, "%lu\n",
59 (part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
60 sbi->s_sectors_written_start) >> 1);
61}
62
63static ssize_t lifetime_write_kbytes_show(struct ext4_sb_info *sbi, char *buf)
64{
65 struct super_block *sb = sbi->s_buddy_cache->i_sb;
66
67 if (!sb->s_bdev->bd_part)
68 return snprintf(buf, PAGE_SIZE, "0\n");
69 return snprintf(buf, PAGE_SIZE, "%llu\n",
70 (unsigned long long)(sbi->s_kbytes_written +
71 ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
72 EXT4_SB(sb)->s_sectors_written_start) >> 1)));
73}
74
75static ssize_t inode_readahead_blks_store(struct ext4_sb_info *sbi,
76 const char *buf, size_t count)
77{
78 unsigned long t;
79 int ret;
80
81 ret = kstrtoul(skip_spaces(buf), 0, &t);
82 if (ret)
83 return ret;
84
85 if (t && (!is_power_of_2(t) || t > 0x40000000))
86 return -EINVAL;
87
88 sbi->s_inode_readahead_blks = t;
89 return count;
90}
91
92static ssize_t reserved_clusters_store(struct ext4_sb_info *sbi,
93 const char *buf, size_t count)
94{
95 unsigned long long val;
96 ext4_fsblk_t clusters = (ext4_blocks_count(sbi->s_es) >>
97 sbi->s_cluster_bits);
98 int ret;
99
100 ret = kstrtoull(skip_spaces(buf), 0, &val);
101 if (ret || val >= clusters)
102 return -EINVAL;
103
104 atomic64_set(&sbi->s_resv_clusters, val);
105 return count;
106}
107
108static ssize_t trigger_test_error(struct ext4_sb_info *sbi,
109 const char *buf, size_t count)
110{
111 int len = count;
112
113 if (!capable(CAP_SYS_ADMIN))
114 return -EPERM;
115
116 if (len && buf[len-1] == '\n')
117 len--;
118
119 if (len)
120 ext4_error(sbi->s_sb, "%.*s", len, buf);
121 return count;
122}
123
124#define EXT4_ATTR(_name,_mode,_id) \
125static struct ext4_attr ext4_attr_##_name = { \
126 .attr = {.name = __stringify(_name), .mode = _mode }, \
127 .attr_id = attr_##_id, \
128}
129
130#define EXT4_ATTR_FUNC(_name,_mode) EXT4_ATTR(_name,_mode,_name)
131
132#define EXT4_ATTR_FEATURE(_name) EXT4_ATTR(_name, 0444, feature)
133
134#define EXT4_ATTR_OFFSET(_name,_mode,_id,_struct,_elname) \
135static struct ext4_attr ext4_attr_##_name = { \
136 .attr = {.name = __stringify(_name), .mode = _mode }, \
137 .attr_id = attr_##_id, \
138 .attr_ptr = ptr_##_struct##_offset, \
139 .u = { \
140 .offset = offsetof(struct _struct, _elname),\
141 }, \
142}
143
144#define EXT4_RO_ATTR_ES_UI(_name,_elname) \
145 EXT4_ATTR_OFFSET(_name, 0444, pointer_ui, ext4_super_block, _elname)
146
147#define EXT4_RW_ATTR_SBI_UI(_name,_elname) \
148 EXT4_ATTR_OFFSET(_name, 0644, pointer_ui, ext4_sb_info, _elname)
149
150#define EXT4_ATTR_PTR(_name,_mode,_id,_ptr) \
151static struct ext4_attr ext4_attr_##_name = { \
152 .attr = {.name = __stringify(_name), .mode = _mode }, \
153 .attr_id = attr_##_id, \
154 .attr_ptr = ptr_explicit, \
155 .u = { \
156 .explicit_ptr = _ptr, \
157 }, \
158}
159
160#define ATTR_LIST(name) &ext4_attr_##name.attr
161
162EXT4_ATTR_FUNC(delayed_allocation_blocks, 0444);
163EXT4_ATTR_FUNC(session_write_kbytes, 0444);
164EXT4_ATTR_FUNC(lifetime_write_kbytes, 0444);
165EXT4_ATTR_FUNC(reserved_clusters, 0644);
166
167EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, inode_readahead,
168 ext4_sb_info, s_inode_readahead_blks);
169EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
170EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
171EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
172EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
173EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
174EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
175EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
176EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
177EXT4_ATTR(trigger_fs_error, 0200, trigger_test_error);
178EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);
179EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst);
180EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);
181EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst);
182EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval);
183EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst);
184EXT4_RO_ATTR_ES_UI(errors_count, s_error_count);
185EXT4_RO_ATTR_ES_UI(first_error_time, s_first_error_time);
186EXT4_RO_ATTR_ES_UI(last_error_time, s_last_error_time);
187
188static unsigned int old_bump_val = 128;
189EXT4_ATTR_PTR(max_writeback_mb_bump, 0444, pointer_ui, &old_bump_val);
190
191static struct attribute *ext4_attrs[] = {
192 ATTR_LIST(delayed_allocation_blocks),
193 ATTR_LIST(session_write_kbytes),
194 ATTR_LIST(lifetime_write_kbytes),
195 ATTR_LIST(reserved_clusters),
196 ATTR_LIST(inode_readahead_blks),
197 ATTR_LIST(inode_goal),
198 ATTR_LIST(mb_stats),
199 ATTR_LIST(mb_max_to_scan),
200 ATTR_LIST(mb_min_to_scan),
201 ATTR_LIST(mb_order2_req),
202 ATTR_LIST(mb_stream_req),
203 ATTR_LIST(mb_group_prealloc),
204 ATTR_LIST(max_writeback_mb_bump),
205 ATTR_LIST(extent_max_zeroout_kb),
206 ATTR_LIST(trigger_fs_error),
207 ATTR_LIST(err_ratelimit_interval_ms),
208 ATTR_LIST(err_ratelimit_burst),
209 ATTR_LIST(warning_ratelimit_interval_ms),
210 ATTR_LIST(warning_ratelimit_burst),
211 ATTR_LIST(msg_ratelimit_interval_ms),
212 ATTR_LIST(msg_ratelimit_burst),
213 ATTR_LIST(errors_count),
214 ATTR_LIST(first_error_time),
215 ATTR_LIST(last_error_time),
216 NULL,
217};
218
219/* Features this copy of ext4 supports */
220EXT4_ATTR_FEATURE(lazy_itable_init);
221EXT4_ATTR_FEATURE(batched_discard);
222EXT4_ATTR_FEATURE(meta_bg_resize);
223#ifdef CONFIG_EXT4_FS_ENCRYPTION
224EXT4_ATTR_FEATURE(encryption);
225#endif
226EXT4_ATTR_FEATURE(metadata_csum_seed);
227
228static struct attribute *ext4_feat_attrs[] = {
229 ATTR_LIST(lazy_itable_init),
230 ATTR_LIST(batched_discard),
231 ATTR_LIST(meta_bg_resize),
232#ifdef CONFIG_EXT4_FS_ENCRYPTION
233 ATTR_LIST(encryption),
234#endif
235 ATTR_LIST(metadata_csum_seed),
236 NULL,
237};
238
239static void *calc_ptr(struct ext4_attr *a, struct ext4_sb_info *sbi)
240{
241 switch (a->attr_ptr) {
242 case ptr_explicit:
243 return a->u.explicit_ptr;
244 case ptr_ext4_sb_info_offset:
245 return (void *) (((char *) sbi) + a->u.offset);
246 case ptr_ext4_super_block_offset:
247 return (void *) (((char *) sbi->s_es) + a->u.offset);
248 }
249 return NULL;
250}
251
252static ssize_t ext4_attr_show(struct kobject *kobj,
253 struct attribute *attr, char *buf)
254{
255 struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
256 s_kobj);
257 struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
258 void *ptr = calc_ptr(a, sbi);
259
260 switch (a->attr_id) {
261 case attr_delayed_allocation_blocks:
262 return snprintf(buf, PAGE_SIZE, "%llu\n",
263 (s64) EXT4_C2B(sbi,
264 percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
265 case attr_session_write_kbytes:
266 return session_write_kbytes_show(sbi, buf);
267 case attr_lifetime_write_kbytes:
268 return lifetime_write_kbytes_show(sbi, buf);
269 case attr_reserved_clusters:
270 return snprintf(buf, PAGE_SIZE, "%llu\n",
271 (unsigned long long)
272 atomic64_read(&sbi->s_resv_clusters));
273 case attr_inode_readahead:
274 case attr_pointer_ui:
275 if (!ptr)
276 return 0;
277 return snprintf(buf, PAGE_SIZE, "%u\n",
278 *((unsigned int *) ptr));
279 case attr_pointer_atomic:
280 if (!ptr)
281 return 0;
282 return snprintf(buf, PAGE_SIZE, "%d\n",
283 atomic_read((atomic_t *) ptr));
284 case attr_feature:
285 return snprintf(buf, PAGE_SIZE, "supported\n");
286 }
287
288 return 0;
289}
290
291static ssize_t ext4_attr_store(struct kobject *kobj,
292 struct attribute *attr,
293 const char *buf, size_t len)
294{
295 struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
296 s_kobj);
297 struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
298 void *ptr = calc_ptr(a, sbi);
299 unsigned long t;
300 int ret;
301
302 switch (a->attr_id) {
303 case attr_reserved_clusters:
304 return reserved_clusters_store(sbi, buf, len);
305 case attr_pointer_ui:
306 if (!ptr)
307 return 0;
308 ret = kstrtoul(skip_spaces(buf), 0, &t);
309 if (ret)
310 return ret;
311 *((unsigned int *) ptr) = t;
312 return len;
313 case attr_inode_readahead:
314 return inode_readahead_blks_store(sbi, buf, len);
315 case attr_trigger_test_error:
316 return trigger_test_error(sbi, buf, len);
317 }
318 return 0;
319}
320
321static void ext4_sb_release(struct kobject *kobj)
322{
323 struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
324 s_kobj);
325 complete(&sbi->s_kobj_unregister);
326}
327
328static const struct sysfs_ops ext4_attr_ops = {
329 .show = ext4_attr_show,
330 .store = ext4_attr_store,
331};
332
333static struct kobj_type ext4_sb_ktype = {
334 .default_attrs = ext4_attrs,
335 .sysfs_ops = &ext4_attr_ops,
336 .release = ext4_sb_release,
337};
338
339static struct kobj_type ext4_feat_ktype = {
340 .default_attrs = ext4_feat_attrs,
341 .sysfs_ops = &ext4_attr_ops,
342 .release = (void (*)(struct kobject *))kfree,
343};
344
345static struct kobject *ext4_root;
346
347static struct kobject *ext4_feat;
348
349#define PROC_FILE_SHOW_DEFN(name) \
350static int name##_open(struct inode *inode, struct file *file) \
351{ \
352 return single_open(file, ext4_seq_##name##_show, PDE_DATA(inode)); \
353} \
354\
355static const struct file_operations ext4_seq_##name##_fops = { \
356 .open = name##_open, \
357 .read = seq_read, \
358 .llseek = seq_lseek, \
359 .release = single_release, \
360}
361
362#define PROC_FILE_LIST(name) \
363 { __stringify(name), &ext4_seq_##name##_fops }
364
365PROC_FILE_SHOW_DEFN(es_shrinker_info);
366PROC_FILE_SHOW_DEFN(options);
367
368static const struct ext4_proc_files {
369 const char *name;
370 const struct file_operations *fops;
371} proc_files[] = {
372 PROC_FILE_LIST(options),
373 PROC_FILE_LIST(es_shrinker_info),
374 PROC_FILE_LIST(mb_groups),
375 { NULL, NULL },
376};
377
378int ext4_register_sysfs(struct super_block *sb)
379{
380 struct ext4_sb_info *sbi = EXT4_SB(sb);
381 const struct ext4_proc_files *p;
382 int err;
383
384 init_completion(&sbi->s_kobj_unregister);
385 err = kobject_init_and_add(&sbi->s_kobj, &ext4_sb_ktype, ext4_root,
386 "%s", sb->s_id);
387 if (err) {
388 kobject_put(&sbi->s_kobj);
389 wait_for_completion(&sbi->s_kobj_unregister);
390 return err;
391 }
392
393 if (ext4_proc_root)
394 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
395
396 if (sbi->s_proc) {
397 for (p = proc_files; p->name; p++)
398 proc_create_data(p->name, S_IRUGO, sbi->s_proc,
399 p->fops, sb);
400 }
401 return 0;
402}
403
404void ext4_unregister_sysfs(struct super_block *sb)
405{
406 struct ext4_sb_info *sbi = EXT4_SB(sb);
407 const struct ext4_proc_files *p;
408
409 if (sbi->s_proc) {
410 for (p = proc_files; p->name; p++)
411 remove_proc_entry(p->name, sbi->s_proc);
412 remove_proc_entry(sb->s_id, ext4_proc_root);
413 }
414 kobject_del(&sbi->s_kobj);
415}
416
417int __init ext4_init_sysfs(void)
418{
419 int ret;
420
421 ext4_root = kobject_create_and_add("ext4", fs_kobj);
422 if (!ext4_root)
423 return -ENOMEM;
424
425 ext4_feat = kzalloc(sizeof(*ext4_feat), GFP_KERNEL);
426 if (!ext4_feat) {
427 ret = -ENOMEM;
428 goto root_err;
429 }
430
431 ret = kobject_init_and_add(ext4_feat, &ext4_feat_ktype,
432 ext4_root, "features");
433 if (ret)
434 goto feat_err;
435
436 ext4_proc_root = proc_mkdir(proc_dirname, NULL);
437 return ret;
438
439feat_err:
440 kobject_put(ext4_feat);
441 ext4_feat = NULL;
442root_err:
443 kobject_put(ext4_root);
444 ext4_root = NULL;
445 return ret;
446}
447
448void ext4_exit_sysfs(void)
449{
450 kobject_put(ext4_feat);
451 ext4_feat = NULL;
452 kobject_put(ext4_root);
453 ext4_root = NULL;
454 remove_proc_entry(proc_dirname, NULL);
455 ext4_proc_root = NULL;
456}
457