Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target...
[sfrench/cifs-2.6.git] / fs / ext4 / sysfs.c
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_feature,
29         attr_pointer_ui,
30         attr_pointer_atomic,
31 } attr_id_t;
32
33 typedef enum {
34         ptr_explicit,
35         ptr_ext4_sb_info_offset,
36         ptr_ext4_super_block_offset,
37 } attr_ptr_t;
38
39 static const char proc_dirname[] = "fs/ext4";
40 static struct proc_dir_entry *ext4_proc_root;
41
42 struct 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
52 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
53                                          struct ext4_sb_info *sbi, char *buf)
54 {
55         struct super_block *sb = sbi->s_buddy_cache->i_sb;
56
57         if (!sb->s_bdev->bd_part)
58                 return snprintf(buf, PAGE_SIZE, "0\n");
59         return snprintf(buf, PAGE_SIZE, "%lu\n",
60                         (part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
61                          sbi->s_sectors_written_start) >> 1);
62 }
63
64 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
65                                           struct ext4_sb_info *sbi, char *buf)
66 {
67         struct super_block *sb = sbi->s_buddy_cache->i_sb;
68
69         if (!sb->s_bdev->bd_part)
70                 return snprintf(buf, PAGE_SIZE, "0\n");
71         return snprintf(buf, PAGE_SIZE, "%llu\n",
72                         (unsigned long long)(sbi->s_kbytes_written +
73                         ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
74                           EXT4_SB(sb)->s_sectors_written_start) >> 1)));
75 }
76
77 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
78                                           struct ext4_sb_info *sbi,
79                                           const char *buf, size_t count)
80 {
81         unsigned long t;
82         int ret;
83
84         ret = kstrtoul(skip_spaces(buf), 0, &t);
85         if (ret)
86                 return ret;
87
88         if (t && (!is_power_of_2(t) || t > 0x40000000))
89                 return -EINVAL;
90
91         sbi->s_inode_readahead_blks = t;
92         return count;
93 }
94
95 static ssize_t reserved_clusters_store(struct ext4_attr *a,
96                                    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
112 static ssize_t trigger_test_error(struct ext4_attr *a,
113                                   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
129 #define EXT4_ATTR(_name,_mode,_id)                                      \
130 static struct ext4_attr ext4_attr_##_name = {                           \
131         .attr = {.name = __stringify(_name), .mode = _mode },           \
132         .attr_id = attr_##_id,                                          \
133 }
134
135 #define EXT4_ATTR_FUNC(_name,_mode)  EXT4_ATTR(_name,_mode,_name)
136
137 #define EXT4_ATTR_FEATURE(_name)   EXT4_ATTR(_name, 0444, feature)
138
139 #define EXT4_ATTR_OFFSET(_name,_mode,_id,_struct,_elname)       \
140 static struct ext4_attr ext4_attr_##_name = {                   \
141         .attr = {.name = __stringify(_name), .mode = _mode },   \
142         .attr_id = attr_##_id,                                  \
143         .attr_ptr = ptr_##_struct##_offset,                     \
144         .u = {                                                  \
145                 .offset = offsetof(struct _struct, _elname),\
146         },                                                      \
147 }
148
149 #define EXT4_RO_ATTR_ES_UI(_name,_elname)                               \
150         EXT4_ATTR_OFFSET(_name, 0444, pointer_ui, ext4_super_block, _elname)
151
152 #define EXT4_RW_ATTR_SBI_UI(_name,_elname)      \
153         EXT4_ATTR_OFFSET(_name, 0644, pointer_ui, ext4_sb_info, _elname)
154
155 #define EXT4_ATTR_PTR(_name,_mode,_id,_ptr) \
156 static struct ext4_attr ext4_attr_##_name = {                   \
157         .attr = {.name = __stringify(_name), .mode = _mode },   \
158         .attr_id = attr_##_id,                                  \
159         .attr_ptr = ptr_explicit,                               \
160         .u = {                                                  \
161                 .explicit_ptr = _ptr,                           \
162         },                                                      \
163 }
164
165 #define ATTR_LIST(name) &ext4_attr_##name.attr
166
167 EXT4_ATTR_FUNC(delayed_allocation_blocks, 0444);
168 EXT4_ATTR_FUNC(session_write_kbytes, 0444);
169 EXT4_ATTR_FUNC(lifetime_write_kbytes, 0444);
170 EXT4_ATTR_FUNC(reserved_clusters, 0644);
171
172 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, inode_readahead,
173                  ext4_sb_info, s_inode_readahead_blks);
174 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
175 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
176 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
177 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
178 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
179 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
180 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
181 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
182 EXT4_ATTR(trigger_fs_error, 0200, trigger_test_error);
183 EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);
184 EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst);
185 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);
186 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst);
187 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval);
188 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst);
189 EXT4_RO_ATTR_ES_UI(errors_count, s_error_count);
190 EXT4_RO_ATTR_ES_UI(first_error_time, s_first_error_time);
191 EXT4_RO_ATTR_ES_UI(last_error_time, s_last_error_time);
192
193 static unsigned int old_bump_val = 128;
194 EXT4_ATTR_PTR(max_writeback_mb_bump, 0444, pointer_ui, &old_bump_val);
195
196 static struct attribute *ext4_attrs[] = {
197         ATTR_LIST(delayed_allocation_blocks),
198         ATTR_LIST(session_write_kbytes),
199         ATTR_LIST(lifetime_write_kbytes),
200         ATTR_LIST(reserved_clusters),
201         ATTR_LIST(inode_readahead_blks),
202         ATTR_LIST(inode_goal),
203         ATTR_LIST(mb_stats),
204         ATTR_LIST(mb_max_to_scan),
205         ATTR_LIST(mb_min_to_scan),
206         ATTR_LIST(mb_order2_req),
207         ATTR_LIST(mb_stream_req),
208         ATTR_LIST(mb_group_prealloc),
209         ATTR_LIST(max_writeback_mb_bump),
210         ATTR_LIST(extent_max_zeroout_kb),
211         ATTR_LIST(trigger_fs_error),
212         ATTR_LIST(err_ratelimit_interval_ms),
213         ATTR_LIST(err_ratelimit_burst),
214         ATTR_LIST(warning_ratelimit_interval_ms),
215         ATTR_LIST(warning_ratelimit_burst),
216         ATTR_LIST(msg_ratelimit_interval_ms),
217         ATTR_LIST(msg_ratelimit_burst),
218         ATTR_LIST(errors_count),
219         ATTR_LIST(first_error_time),
220         ATTR_LIST(last_error_time),
221         NULL,
222 };
223
224 /* Features this copy of ext4 supports */
225 EXT4_ATTR_FEATURE(lazy_itable_init);
226 EXT4_ATTR_FEATURE(batched_discard);
227 EXT4_ATTR_FEATURE(meta_bg_resize);
228 #ifdef CONFIG_EXT4_FS_ENCRYPTION
229 EXT4_ATTR_FEATURE(encryption);
230 #endif
231 EXT4_ATTR_FEATURE(metadata_csum_seed);
232
233 static struct attribute *ext4_feat_attrs[] = {
234         ATTR_LIST(lazy_itable_init),
235         ATTR_LIST(batched_discard),
236         ATTR_LIST(meta_bg_resize),
237 #ifdef CONFIG_EXT4_FS_ENCRYPTION
238         ATTR_LIST(encryption),
239 #endif
240         ATTR_LIST(metadata_csum_seed),
241         NULL,
242 };
243
244 static void *calc_ptr(struct ext4_attr *a, struct ext4_sb_info *sbi)
245 {
246         switch (a->attr_ptr) {
247         case ptr_explicit:
248                 return a->u.explicit_ptr;
249         case ptr_ext4_sb_info_offset:
250                 return (void *) (((char *) sbi) + a->u.offset);
251         case ptr_ext4_super_block_offset:
252                 return (void *) (((char *) sbi->s_es) + a->u.offset);
253         }
254         return NULL;
255 }
256
257 static ssize_t ext4_attr_show(struct kobject *kobj,
258                               struct attribute *attr, char *buf)
259 {
260         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
261                                                 s_kobj);
262         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
263         void *ptr = calc_ptr(a, sbi);
264
265         switch (a->attr_id) {
266         case attr_delayed_allocation_blocks:
267                 return snprintf(buf, PAGE_SIZE, "%llu\n",
268                                 (s64) EXT4_C2B(sbi,
269                        percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
270         case attr_session_write_kbytes:
271                 return session_write_kbytes_show(a, sbi, buf);
272         case attr_lifetime_write_kbytes:
273                 return lifetime_write_kbytes_show(a, sbi, buf);
274         case attr_reserved_clusters:
275                 return snprintf(buf, PAGE_SIZE, "%llu\n",
276                                 (unsigned long long)
277                                 atomic64_read(&sbi->s_resv_clusters));
278         case attr_inode_readahead:
279         case attr_pointer_ui:
280                 if (!ptr)
281                         return 0;
282                 return snprintf(buf, PAGE_SIZE, "%u\n",
283                                 *((unsigned int *) ptr));
284         case attr_pointer_atomic:
285                 if (!ptr)
286                         return 0;
287                 return snprintf(buf, PAGE_SIZE, "%d\n",
288                                 atomic_read((atomic_t *) ptr));
289         case attr_feature:
290                 return snprintf(buf, PAGE_SIZE, "supported\n");
291         }
292
293         return 0;
294 }
295
296 static ssize_t ext4_attr_store(struct kobject *kobj,
297                                struct attribute *attr,
298                                const char *buf, size_t len)
299 {
300         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
301                                                 s_kobj);
302         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
303         void *ptr = calc_ptr(a, sbi);
304         unsigned long t;
305         int ret;
306
307         switch (a->attr_id) {
308         case attr_reserved_clusters:
309                 return reserved_clusters_store(a, sbi, buf, len);
310         case attr_pointer_ui:
311                 if (!ptr)
312                         return 0;
313                 ret = kstrtoul(skip_spaces(buf), 0, &t);
314                 if (ret)
315                         return ret;
316                 *((unsigned int *) ptr) = t;
317                 return len;
318         case attr_inode_readahead:
319                 return inode_readahead_blks_store(a, sbi, buf, len);
320         case attr_trigger_test_error:
321                 return trigger_test_error(a, sbi, buf, len);
322         }
323         return 0;
324 }
325
326 static void ext4_sb_release(struct kobject *kobj)
327 {
328         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
329                                                 s_kobj);
330         complete(&sbi->s_kobj_unregister);
331 }
332
333 static void ext4_kset_release(struct kobject *kobj)
334 {
335         struct kset *kset = container_of(kobj, struct kset, kobj);
336
337         kfree(kset);
338 }
339
340 static const struct sysfs_ops ext4_attr_ops = {
341         .show   = ext4_attr_show,
342         .store  = ext4_attr_store,
343 };
344
345 static struct kobj_type ext4_sb_ktype = {
346         .default_attrs  = ext4_attrs,
347         .sysfs_ops      = &ext4_attr_ops,
348         .release        = ext4_sb_release,
349 };
350
351 static struct kobj_type ext4_ktype = {
352         .sysfs_ops      = &ext4_attr_ops,
353         .release        = ext4_kset_release,
354 };
355
356 static struct kset *ext4_kset;
357
358 static struct kobj_type ext4_feat_ktype = {
359         .default_attrs  = ext4_feat_attrs,
360         .sysfs_ops      = &ext4_attr_ops,
361         .release        = (void (*)(struct kobject *))kfree,
362 };
363
364 static struct kobject *ext4_feat;
365
366 #define PROC_FILE_SHOW_DEFN(name) \
367 static int name##_open(struct inode *inode, struct file *file) \
368 { \
369         return single_open(file, ext4_seq_##name##_show, PDE_DATA(inode)); \
370 } \
371 \
372 static const struct file_operations ext4_seq_##name##_fops = { \
373         .open           = name##_open, \
374         .read           = seq_read, \
375         .llseek         = seq_lseek, \
376         .release        = single_release, \
377 }
378
379 #define PROC_FILE_LIST(name) \
380         { __stringify(name), &ext4_seq_##name##_fops }
381
382 PROC_FILE_SHOW_DEFN(es_shrinker_info);
383 PROC_FILE_SHOW_DEFN(options);
384
385 static const struct ext4_proc_files {
386         const char *name;
387         const struct file_operations *fops;
388 } proc_files[] = {
389         PROC_FILE_LIST(options),
390         PROC_FILE_LIST(es_shrinker_info),
391         PROC_FILE_LIST(mb_groups),
392         { NULL, NULL },
393 };
394
395 int ext4_register_sysfs(struct super_block *sb)
396 {
397         struct ext4_sb_info *sbi = EXT4_SB(sb);
398         const struct ext4_proc_files *p;
399         int err;
400
401         sbi->s_kobj.kset = ext4_kset;
402         init_completion(&sbi->s_kobj_unregister);
403         err = kobject_init_and_add(&sbi->s_kobj, &ext4_sb_ktype, NULL,
404                                    "%s", sb->s_id);
405         if (err) {
406                 kobject_put(&sbi->s_kobj);
407                 wait_for_completion(&sbi->s_kobj_unregister);
408                 return err;
409         }
410
411         if (ext4_proc_root)
412                 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
413
414         if (sbi->s_proc) {
415                 for (p = proc_files; p->name; p++)
416                         proc_create_data(p->name, S_IRUGO, sbi->s_proc,
417                                          p->fops, sb);
418         }
419         return 0;
420 }
421
422 void ext4_unregister_sysfs(struct super_block *sb)
423 {
424         struct ext4_sb_info *sbi = EXT4_SB(sb);
425         const struct ext4_proc_files *p;
426
427         if (sbi->s_proc) {
428                 for (p = proc_files; p->name; p++)
429                         remove_proc_entry(p->name, sbi->s_proc);
430                 remove_proc_entry(sb->s_id, ext4_proc_root);
431         }
432         kobject_del(&sbi->s_kobj);
433 }
434
435 int __init ext4_init_sysfs(void)
436 {
437         int ret;
438
439         ext4_kset = kzalloc(sizeof(*ext4_kset), GFP_KERNEL);
440         if (!ext4_kset)
441                 return -ENOMEM;
442
443         kobject_set_name(&ext4_kset->kobj, "ext4");
444         ext4_kset->kobj.parent = fs_kobj;
445         ext4_kset->kobj.ktype = &ext4_ktype;
446         ret = kset_register(ext4_kset);
447         if (ret)
448                 goto kset_err;
449
450         ext4_feat = kzalloc(sizeof(*ext4_feat), GFP_KERNEL);
451         if (!ext4_feat) {
452                 ret = -ENOMEM;
453                 goto kset_err;
454         }
455
456         ext4_feat->kset = ext4_kset;
457         ret = kobject_init_and_add(ext4_feat, &ext4_feat_ktype,
458                                    NULL, "features");
459         if (ret)
460                 goto feat_err;
461
462         ext4_proc_root = proc_mkdir(proc_dirname, NULL);
463         return ret;
464
465 feat_err:
466         kobject_put(ext4_feat);
467 kset_err:
468         kset_unregister(ext4_kset);
469         ext4_kset = NULL;
470         return ret;
471 }
472
473 void ext4_exit_sysfs(void)
474 {
475         kobject_put(ext4_feat);
476         kset_unregister(ext4_kset);
477         ext4_kset = NULL;
478         remove_proc_entry(proc_dirname, NULL);
479         ext4_proc_root = NULL;
480 }
481