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
20 typedef 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_id_t;
34
35 typedef enum {
36 ptr_explicit,
37 ptr_ext4_sb_info_offset,
38 ptr_ext4_super_block_offset,
39 } attr_ptr_t;
40
41 static const char proc_dirname[] = "fs/ext4";
42 static struct proc_dir_entry *ext4_proc_root;
43
44 struct ext4_attr {
45 struct attribute attr;
46 short attr_id;
47 short attr_ptr;
48 union {
49 int offset;
50 void *explicit_ptr;
51 } u;
52 };
53
session_write_kbytes_show(struct ext4_sb_info * sbi,char * buf)54 static ssize_t session_write_kbytes_show(struct ext4_sb_info *sbi, char *buf)
55 {
56 struct super_block *sb = sbi->s_buddy_cache->i_sb;
57
58 if (!sb->s_bdev->bd_part)
59 return snprintf(buf, PAGE_SIZE, "0\n");
60 return snprintf(buf, PAGE_SIZE, "%lu\n",
61 (part_stat_read(sb->s_bdev->bd_part,
62 sectors[STAT_WRITE]) -
63 sbi->s_sectors_written_start) >> 1);
64 }
65
lifetime_write_kbytes_show(struct ext4_sb_info * sbi,char * buf)66 static ssize_t lifetime_write_kbytes_show(struct ext4_sb_info *sbi, char *buf)
67 {
68 struct super_block *sb = sbi->s_buddy_cache->i_sb;
69
70 if (!sb->s_bdev->bd_part)
71 return snprintf(buf, PAGE_SIZE, "0\n");
72 return snprintf(buf, PAGE_SIZE, "%llu\n",
73 (unsigned long long)(sbi->s_kbytes_written +
74 ((part_stat_read(sb->s_bdev->bd_part,
75 sectors[STAT_WRITE]) -
76 EXT4_SB(sb)->s_sectors_written_start) >> 1)));
77 }
78
inode_readahead_blks_store(struct ext4_sb_info * sbi,const char * buf,size_t count)79 static ssize_t inode_readahead_blks_store(struct ext4_sb_info *sbi,
80 const char *buf, size_t count)
81 {
82 unsigned long t;
83 int ret;
84
85 ret = kstrtoul(skip_spaces(buf), 0, &t);
86 if (ret)
87 return ret;
88
89 if (t && (!is_power_of_2(t) || t > 0x40000000))
90 return -EINVAL;
91
92 sbi->s_inode_readahead_blks = t;
93 return count;
94 }
95
reserved_clusters_store(struct ext4_sb_info * sbi,const char * buf,size_t count)96 static ssize_t reserved_clusters_store(struct ext4_sb_info *sbi,
97 const char *buf, size_t count)
98 {
99 unsigned long long val;
100 ext4_fsblk_t clusters = (ext4_blocks_count(sbi->s_es) >>
101 sbi->s_cluster_bits);
102 int ret;
103
104 ret = kstrtoull(skip_spaces(buf), 0, &val);
105 if (ret || val >= clusters)
106 return -EINVAL;
107
108 atomic64_set(&sbi->s_resv_clusters, val);
109 return count;
110 }
111
trigger_test_error(struct ext4_sb_info * sbi,const char * buf,size_t count)112 static ssize_t trigger_test_error(struct ext4_sb_info *sbi,
113 const char *buf, size_t count)
114 {
115 int len = count;
116
117 if (!capable(CAP_SYS_ADMIN))
118 return -EPERM;
119
120 if (len && buf[len-1] == '\n')
121 len--;
122
123 if (len)
124 ext4_error(sbi->s_sb, "%.*s", len, buf);
125 return count;
126 }
127
128 #define EXT4_ATTR(_name,_mode,_id) \
129 static struct ext4_attr ext4_attr_##_name = { \
130 .attr = {.name = __stringify(_name), .mode = _mode }, \
131 .attr_id = attr_##_id, \
132 }
133
134 #define EXT4_ATTR_FUNC(_name,_mode) EXT4_ATTR(_name,_mode,_name)
135
136 #define EXT4_ATTR_FEATURE(_name) EXT4_ATTR(_name, 0444, feature)
137
138 #define EXT4_ATTR_OFFSET(_name,_mode,_id,_struct,_elname) \
139 static struct ext4_attr ext4_attr_##_name = { \
140 .attr = {.name = __stringify(_name), .mode = _mode }, \
141 .attr_id = attr_##_id, \
142 .attr_ptr = ptr_##_struct##_offset, \
143 .u = { \
144 .offset = offsetof(struct _struct, _elname),\
145 }, \
146 }
147
148 #define EXT4_RO_ATTR_ES_UI(_name,_elname) \
149 EXT4_ATTR_OFFSET(_name, 0444, pointer_ui, ext4_super_block, _elname)
150
151 #define EXT4_RW_ATTR_SBI_UI(_name,_elname) \
152 EXT4_ATTR_OFFSET(_name, 0644, pointer_ui, ext4_sb_info, _elname)
153
154 #define EXT4_ATTR_PTR(_name,_mode,_id,_ptr) \
155 static struct ext4_attr ext4_attr_##_name = { \
156 .attr = {.name = __stringify(_name), .mode = _mode }, \
157 .attr_id = attr_##_id, \
158 .attr_ptr = ptr_explicit, \
159 .u = { \
160 .explicit_ptr = _ptr, \
161 }, \
162 }
163
164 #define ATTR_LIST(name) &ext4_attr_##name.attr
165
166 EXT4_ATTR_FUNC(delayed_allocation_blocks, 0444);
167 EXT4_ATTR_FUNC(session_write_kbytes, 0444);
168 EXT4_ATTR_FUNC(lifetime_write_kbytes, 0444);
169 EXT4_ATTR_FUNC(reserved_clusters, 0644);
170
171 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, inode_readahead,
172 ext4_sb_info, s_inode_readahead_blks);
173 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
174 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
175 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
176 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
177 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
178 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
179 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
180 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
181 EXT4_ATTR(trigger_fs_error, 0200, trigger_test_error);
182 EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);
183 EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst);
184 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);
185 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst);
186 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval);
187 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst);
188 EXT4_RO_ATTR_ES_UI(errors_count, s_error_count);
189 EXT4_ATTR(first_error_time, 0444, first_error_time);
190 EXT4_ATTR(last_error_time, 0444, last_error_time);
191
192 static unsigned int old_bump_val = 128;
193 EXT4_ATTR_PTR(max_writeback_mb_bump, 0444, pointer_ui, &old_bump_val);
194
195 static struct attribute *ext4_attrs[] = {
196 ATTR_LIST(delayed_allocation_blocks),
197 ATTR_LIST(session_write_kbytes),
198 ATTR_LIST(lifetime_write_kbytes),
199 ATTR_LIST(reserved_clusters),
200 ATTR_LIST(inode_readahead_blks),
201 ATTR_LIST(inode_goal),
202 ATTR_LIST(mb_stats),
203 ATTR_LIST(mb_max_to_scan),
204 ATTR_LIST(mb_min_to_scan),
205 ATTR_LIST(mb_order2_req),
206 ATTR_LIST(mb_stream_req),
207 ATTR_LIST(mb_group_prealloc),
208 ATTR_LIST(max_writeback_mb_bump),
209 ATTR_LIST(extent_max_zeroout_kb),
210 ATTR_LIST(trigger_fs_error),
211 ATTR_LIST(err_ratelimit_interval_ms),
212 ATTR_LIST(err_ratelimit_burst),
213 ATTR_LIST(warning_ratelimit_interval_ms),
214 ATTR_LIST(warning_ratelimit_burst),
215 ATTR_LIST(msg_ratelimit_interval_ms),
216 ATTR_LIST(msg_ratelimit_burst),
217 ATTR_LIST(errors_count),
218 ATTR_LIST(first_error_time),
219 ATTR_LIST(last_error_time),
220 NULL,
221 };
222
223 /* Features this copy of ext4 supports */
224 EXT4_ATTR_FEATURE(lazy_itable_init);
225 EXT4_ATTR_FEATURE(batched_discard);
226 EXT4_ATTR_FEATURE(meta_bg_resize);
227 #ifdef CONFIG_EXT4_FS_ENCRYPTION
228 EXT4_ATTR_FEATURE(encryption);
229 #endif
230 EXT4_ATTR_FEATURE(metadata_csum_seed);
231
232 static struct attribute *ext4_feat_attrs[] = {
233 ATTR_LIST(lazy_itable_init),
234 ATTR_LIST(batched_discard),
235 ATTR_LIST(meta_bg_resize),
236 #ifdef CONFIG_EXT4_FS_ENCRYPTION
237 ATTR_LIST(encryption),
238 #endif
239 ATTR_LIST(metadata_csum_seed),
240 NULL,
241 };
242
calc_ptr(struct ext4_attr * a,struct ext4_sb_info * sbi)243 static void *calc_ptr(struct ext4_attr *a, struct ext4_sb_info *sbi)
244 {
245 switch (a->attr_ptr) {
246 case ptr_explicit:
247 return a->u.explicit_ptr;
248 case ptr_ext4_sb_info_offset:
249 return (void *) (((char *) sbi) + a->u.offset);
250 case ptr_ext4_super_block_offset:
251 return (void *) (((char *) sbi->s_es) + a->u.offset);
252 }
253 return NULL;
254 }
255
__print_tstamp(char * buf,__le32 lo,__u8 hi)256 static ssize_t __print_tstamp(char *buf, __le32 lo, __u8 hi)
257 {
258 return snprintf(buf, PAGE_SIZE, "%lld",
259 ((time64_t)hi << 32) + le32_to_cpu(lo));
260 }
261
262 #define print_tstamp(buf, es, tstamp) \
263 __print_tstamp(buf, (es)->tstamp, (es)->tstamp ## _hi)
264
ext4_attr_show(struct kobject * kobj,struct attribute * attr,char * buf)265 static ssize_t ext4_attr_show(struct kobject *kobj,
266 struct attribute *attr, char *buf)
267 {
268 struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
269 s_kobj);
270 struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
271 void *ptr = calc_ptr(a, sbi);
272
273 switch (a->attr_id) {
274 case attr_delayed_allocation_blocks:
275 return snprintf(buf, PAGE_SIZE, "%llu\n",
276 (s64) EXT4_C2B(sbi,
277 percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
278 case attr_session_write_kbytes:
279 return session_write_kbytes_show(sbi, buf);
280 case attr_lifetime_write_kbytes:
281 return lifetime_write_kbytes_show(sbi, buf);
282 case attr_reserved_clusters:
283 return snprintf(buf, PAGE_SIZE, "%llu\n",
284 (unsigned long long)
285 atomic64_read(&sbi->s_resv_clusters));
286 case attr_inode_readahead:
287 case attr_pointer_ui:
288 if (!ptr)
289 return 0;
290 if (a->attr_ptr == ptr_ext4_super_block_offset)
291 return snprintf(buf, PAGE_SIZE, "%u\n",
292 le32_to_cpup(ptr));
293 else
294 return snprintf(buf, PAGE_SIZE, "%u\n",
295 *((unsigned int *) ptr));
296 case attr_pointer_atomic:
297 if (!ptr)
298 return 0;
299 return snprintf(buf, PAGE_SIZE, "%d\n",
300 atomic_read((atomic_t *) ptr));
301 case attr_feature:
302 return snprintf(buf, PAGE_SIZE, "supported\n");
303 case attr_first_error_time:
304 return print_tstamp(buf, sbi->s_es, s_first_error_time);
305 case attr_last_error_time:
306 return print_tstamp(buf, sbi->s_es, s_last_error_time);
307 }
308
309 return 0;
310 }
311
ext4_attr_store(struct kobject * kobj,struct attribute * attr,const char * buf,size_t len)312 static ssize_t ext4_attr_store(struct kobject *kobj,
313 struct attribute *attr,
314 const char *buf, size_t len)
315 {
316 struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
317 s_kobj);
318 struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
319 void *ptr = calc_ptr(a, sbi);
320 unsigned long t;
321 int ret;
322
323 switch (a->attr_id) {
324 case attr_reserved_clusters:
325 return reserved_clusters_store(sbi, buf, len);
326 case attr_pointer_ui:
327 if (!ptr)
328 return 0;
329 ret = kstrtoul(skip_spaces(buf), 0, &t);
330 if (ret)
331 return ret;
332 if (a->attr_ptr == ptr_ext4_super_block_offset)
333 *((__le32 *) ptr) = cpu_to_le32(t);
334 else
335 *((unsigned int *) ptr) = t;
336 return len;
337 case attr_inode_readahead:
338 return inode_readahead_blks_store(sbi, buf, len);
339 case attr_trigger_test_error:
340 return trigger_test_error(sbi, buf, len);
341 }
342 return 0;
343 }
344
ext4_sb_release(struct kobject * kobj)345 static void ext4_sb_release(struct kobject *kobj)
346 {
347 struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
348 s_kobj);
349 complete(&sbi->s_kobj_unregister);
350 }
351
ext4_feat_release(struct kobject * kobj)352 static void ext4_feat_release(struct kobject *kobj)
353 {
354 kfree(kobj);
355 }
356
357 static const struct sysfs_ops ext4_attr_ops = {
358 .show = ext4_attr_show,
359 .store = ext4_attr_store,
360 };
361
362 static struct kobj_type ext4_sb_ktype = {
363 .default_attrs = ext4_attrs,
364 .sysfs_ops = &ext4_attr_ops,
365 .release = ext4_sb_release,
366 };
367
368 static struct kobj_type ext4_feat_ktype = {
369 .default_attrs = ext4_feat_attrs,
370 .sysfs_ops = &ext4_attr_ops,
371 .release = ext4_feat_release,
372 };
373
374 static struct kobject *ext4_root;
375
376 static struct kobject *ext4_feat;
377
ext4_register_sysfs(struct super_block * sb)378 int ext4_register_sysfs(struct super_block *sb)
379 {
380 struct ext4_sb_info *sbi = EXT4_SB(sb);
381 int err;
382
383 init_completion(&sbi->s_kobj_unregister);
384 err = kobject_init_and_add(&sbi->s_kobj, &ext4_sb_ktype, ext4_root,
385 "%s", sb->s_id);
386 if (err) {
387 kobject_put(&sbi->s_kobj);
388 wait_for_completion(&sbi->s_kobj_unregister);
389 return err;
390 }
391
392 if (ext4_proc_root)
393 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
394 if (sbi->s_proc) {
395 proc_create_single_data("options", S_IRUGO, sbi->s_proc,
396 ext4_seq_options_show, sb);
397 proc_create_single_data("es_shrinker_info", S_IRUGO,
398 sbi->s_proc, ext4_seq_es_shrinker_info_show,
399 sb);
400 proc_create_seq_data("mb_groups", S_IRUGO, sbi->s_proc,
401 &ext4_mb_seq_groups_ops, sb);
402 }
403 return 0;
404 }
405
ext4_unregister_sysfs(struct super_block * sb)406 void ext4_unregister_sysfs(struct super_block *sb)
407 {
408 struct ext4_sb_info *sbi = EXT4_SB(sb);
409
410 if (sbi->s_proc)
411 remove_proc_subtree(sb->s_id, ext4_proc_root);
412 kobject_del(&sbi->s_kobj);
413 }
414
ext4_init_sysfs(void)415 int __init ext4_init_sysfs(void)
416 {
417 int ret;
418
419 ext4_root = kobject_create_and_add("ext4", fs_kobj);
420 if (!ext4_root)
421 return -ENOMEM;
422
423 ext4_feat = kzalloc(sizeof(*ext4_feat), GFP_KERNEL);
424 if (!ext4_feat) {
425 ret = -ENOMEM;
426 goto root_err;
427 }
428
429 ret = kobject_init_and_add(ext4_feat, &ext4_feat_ktype,
430 ext4_root, "features");
431 if (ret)
432 goto feat_err;
433
434 ext4_proc_root = proc_mkdir(proc_dirname, NULL);
435 return ret;
436
437 feat_err:
438 kobject_put(ext4_feat);
439 ext4_feat = NULL;
440 root_err:
441 kobject_put(ext4_root);
442 ext4_root = NULL;
443 return ret;
444 }
445
ext4_exit_sysfs(void)446 void ext4_exit_sysfs(void)
447 {
448 kobject_put(ext4_feat);
449 ext4_feat = NULL;
450 kobject_put(ext4_root);
451 ext4_root = NULL;
452 remove_proc_entry(proc_dirname, NULL);
453 ext4_proc_root = NULL;
454 }
455
456