1/*
2 *  linux/fs/ext4/sysfs.c
3 *
4 * Copyright (C) 1992, 1993, 1994, 1995
5 * Remy Card (card@masi.ibp.fr)
6 * Theodore Ts'o (tytso@mit.edu)
7 *
8 */
9
10#include <linux/time.h>
11#include <linux/fs.h>
12#include <linux/seq_file.h>
13#include <linux/proc_fs.h>
14
15#include "ext4.h"
16#include "ext4_jbd2.h"
17
18typedef enum {
19	attr_noop,
20	attr_delayed_allocation_blocks,
21	attr_session_write_kbytes,
22	attr_lifetime_write_kbytes,
23	attr_reserved_clusters,
24	attr_inode_readahead,
25	attr_trigger_test_error,
26	attr_feature,
27	attr_pointer_ui,
28	attr_pointer_atomic,
29} attr_id_t;
30
31typedef enum {
32	ptr_explicit,
33	ptr_ext4_sb_info_offset,
34	ptr_ext4_super_block_offset,
35} attr_ptr_t;
36
37static const char *proc_dirname = "fs/ext4";
38static struct proc_dir_entry *ext4_proc_root;
39
40struct ext4_attr {
41	struct attribute attr;
42	short attr_id;
43	short attr_ptr;
44	union {
45		int offset;
46		void *explicit_ptr;
47	} u;
48};
49
50static ssize_t session_write_kbytes_show(struct ext4_attr *a,
51					 struct ext4_sb_info *sbi, char *buf)
52{
53	struct super_block *sb = sbi->s_buddy_cache->i_sb;
54
55	if (!sb->s_bdev->bd_part)
56		return snprintf(buf, PAGE_SIZE, "0\n");
57	return snprintf(buf, PAGE_SIZE, "%lu\n",
58			(part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
59			 sbi->s_sectors_written_start) >> 1);
60}
61
62static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
63					  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_attr *a,
76					  struct ext4_sb_info *sbi,
77					  const char *buf, size_t count)
78{
79	unsigned long t;
80	int ret;
81
82	ret = kstrtoul(skip_spaces(buf), 0, &t);
83	if (ret)
84		return ret;
85
86	if (t && (!is_power_of_2(t) || t > 0x40000000))
87		return -EINVAL;
88
89	sbi->s_inode_readahead_blks = t;
90	return count;
91}
92
93static ssize_t reserved_clusters_store(struct ext4_attr *a,
94				   struct ext4_sb_info *sbi,
95				   const char *buf, size_t count)
96{
97	unsigned long long val;
98	ext4_fsblk_t clusters = (ext4_blocks_count(sbi->s_es) >>
99				 sbi->s_cluster_bits);
100	int ret;
101
102	ret = kstrtoull(skip_spaces(buf), 0, &val);
103	if (!ret || val >= clusters)
104		return -EINVAL;
105
106	atomic64_set(&sbi->s_resv_clusters, val);
107	return count;
108}
109
110static ssize_t trigger_test_error(struct ext4_attr *a,
111				  struct ext4_sb_info *sbi,
112				  const char *buf, size_t count)
113{
114	int len = count;
115
116	if (!capable(CAP_SYS_ADMIN))
117		return -EPERM;
118
119	if (len && buf[len-1] == '\n')
120		len--;
121
122	if (len)
123		ext4_error(sbi->s_sb, "%.*s", len, buf);
124	return count;
125}
126
127#define EXT4_ATTR(_name,_mode,_id)					\
128static struct ext4_attr ext4_attr_##_name = {				\
129	.attr = {.name = __stringify(_name), .mode = _mode },		\
130	.attr_id = attr_##_id,						\
131}
132
133#define EXT4_ATTR_FUNC(_name,_mode)  EXT4_ATTR(_name,_mode,_name)
134
135#define EXT4_ATTR_FEATURE(_name)   EXT4_ATTR(_name, 0444, feature)
136
137#define EXT4_ATTR_OFFSET(_name,_mode,_id,_struct,_elname)	\
138static struct ext4_attr ext4_attr_##_name = {			\
139	.attr = {.name = __stringify(_name), .mode = _mode },	\
140	.attr_id = attr_##_id,					\
141	.attr_ptr = ptr_##_struct##_offset,			\
142	.u = {							\
143		.offset = offsetof(struct _struct, _elname),\
144	},							\
145}
146
147#define EXT4_RO_ATTR_ES_UI(_name,_elname)				\
148	EXT4_ATTR_OFFSET(_name, 0444, pointer_ui, ext4_super_block, _elname)
149
150#define EXT4_RW_ATTR_SBI_UI(_name,_elname)	\
151	EXT4_ATTR_OFFSET(_name, 0644, pointer_ui, ext4_sb_info, _elname)
152
153#define EXT4_ATTR_PTR(_name,_mode,_id,_ptr) \
154static struct ext4_attr ext4_attr_##_name = {			\
155	.attr = {.name = __stringify(_name), .mode = _mode },	\
156	.attr_id = attr_##_id,					\
157	.attr_ptr = ptr_explicit,				\
158	.u = {							\
159		.explicit_ptr = _ptr,				\
160	},							\
161}
162
163#define ATTR_LIST(name) &ext4_attr_##name.attr
164
165EXT4_ATTR_FUNC(delayed_allocation_blocks, 0444);
166EXT4_ATTR_FUNC(session_write_kbytes, 0444);
167EXT4_ATTR_FUNC(lifetime_write_kbytes, 0444);
168EXT4_ATTR_FUNC(reserved_clusters, 0644);
169
170EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, inode_readahead,
171		 ext4_sb_info, s_inode_readahead_blks);
172EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
173EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
174EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
175EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
176EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
177EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
178EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
179EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
180EXT4_ATTR(trigger_fs_error, 0200, trigger_test_error);
181EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);
182EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst);
183EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);
184EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst);
185EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval);
186EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst);
187EXT4_RO_ATTR_ES_UI(errors_count, s_error_count);
188EXT4_RO_ATTR_ES_UI(first_error_time, s_first_error_time);
189EXT4_RO_ATTR_ES_UI(last_error_time, s_last_error_time);
190
191static unsigned int old_bump_val = 128;
192EXT4_ATTR_PTR(max_writeback_mb_bump, 0444, pointer_ui, &old_bump_val);
193
194static struct attribute *ext4_attrs[] = {
195	ATTR_LIST(delayed_allocation_blocks),
196	ATTR_LIST(session_write_kbytes),
197	ATTR_LIST(lifetime_write_kbytes),
198	ATTR_LIST(reserved_clusters),
199	ATTR_LIST(inode_readahead_blks),
200	ATTR_LIST(inode_goal),
201	ATTR_LIST(mb_stats),
202	ATTR_LIST(mb_max_to_scan),
203	ATTR_LIST(mb_min_to_scan),
204	ATTR_LIST(mb_order2_req),
205	ATTR_LIST(mb_stream_req),
206	ATTR_LIST(mb_group_prealloc),
207	ATTR_LIST(max_writeback_mb_bump),
208	ATTR_LIST(extent_max_zeroout_kb),
209	ATTR_LIST(trigger_fs_error),
210	ATTR_LIST(err_ratelimit_interval_ms),
211	ATTR_LIST(err_ratelimit_burst),
212	ATTR_LIST(warning_ratelimit_interval_ms),
213	ATTR_LIST(warning_ratelimit_burst),
214	ATTR_LIST(msg_ratelimit_interval_ms),
215	ATTR_LIST(msg_ratelimit_burst),
216	ATTR_LIST(errors_count),
217	ATTR_LIST(first_error_time),
218	ATTR_LIST(last_error_time),
219	NULL,
220};
221
222/* Features this copy of ext4 supports */
223EXT4_ATTR_FEATURE(lazy_itable_init);
224EXT4_ATTR_FEATURE(batched_discard);
225EXT4_ATTR_FEATURE(meta_bg_resize);
226EXT4_ATTR_FEATURE(encryption);
227EXT4_ATTR_FEATURE(metadata_csum_seed);
228
229static struct attribute *ext4_feat_attrs[] = {
230	ATTR_LIST(lazy_itable_init),
231	ATTR_LIST(batched_discard),
232	ATTR_LIST(meta_bg_resize),
233	ATTR_LIST(encryption),
234	ATTR_LIST(metadata_csum_seed),
235	NULL,
236};
237
238static void *calc_ptr(struct ext4_attr *a, struct ext4_sb_info *sbi)
239{
240	switch (a->attr_ptr) {
241	case ptr_explicit:
242		return a->u.explicit_ptr;
243	case ptr_ext4_sb_info_offset:
244		return (void *) (((char *) sbi) + a->u.offset);
245	case ptr_ext4_super_block_offset:
246		return (void *) (((char *) sbi->s_es) + a->u.offset);
247	}
248	return NULL;
249}
250
251static ssize_t ext4_attr_show(struct kobject *kobj,
252			      struct attribute *attr, char *buf)
253{
254	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
255						s_kobj);
256	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
257	void *ptr = calc_ptr(a, sbi);
258
259	switch (a->attr_id) {
260	case attr_delayed_allocation_blocks:
261		return snprintf(buf, PAGE_SIZE, "%llu\n",
262				(s64) EXT4_C2B(sbi,
263		       percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
264	case attr_session_write_kbytes:
265		return session_write_kbytes_show(a, sbi, buf);
266	case attr_lifetime_write_kbytes:
267		return lifetime_write_kbytes_show(a, sbi, buf);
268	case attr_reserved_clusters:
269		return snprintf(buf, PAGE_SIZE, "%llu\n",
270				(unsigned long long)
271				atomic64_read(&sbi->s_resv_clusters));
272	case attr_inode_readahead:
273	case attr_pointer_ui:
274		if (!ptr)
275			return 0;
276		return snprintf(buf, PAGE_SIZE, "%u\n",
277				*((unsigned int *) ptr));
278	case attr_pointer_atomic:
279		if (!ptr)
280			return 0;
281		return snprintf(buf, PAGE_SIZE, "%d\n",
282				atomic_read((atomic_t *) ptr));
283	case attr_feature:
284		return snprintf(buf, PAGE_SIZE, "supported\n");
285	}
286
287	return 0;
288}
289
290static ssize_t ext4_attr_store(struct kobject *kobj,
291			       struct attribute *attr,
292			       const char *buf, size_t len)
293{
294	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
295						s_kobj);
296	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
297	void *ptr = calc_ptr(a, sbi);
298	unsigned long t;
299	int ret;
300
301	switch (a->attr_id) {
302	case attr_reserved_clusters:
303		return reserved_clusters_store(a, sbi, buf, len);
304	case attr_pointer_ui:
305		if (!ptr)
306			return 0;
307		ret = kstrtoul(skip_spaces(buf), 0, &t);
308		if (ret)
309			return ret;
310		*((unsigned int *) ptr) = t;
311		return len;
312	case attr_inode_readahead:
313		return inode_readahead_blks_store(a, sbi, buf, len);
314	case attr_trigger_test_error:
315		return trigger_test_error(a, sbi, buf, len);
316	}
317	return 0;
318}
319
320static void ext4_sb_release(struct kobject *kobj)
321{
322	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
323						s_kobj);
324	complete(&sbi->s_kobj_unregister);
325}
326
327static const struct sysfs_ops ext4_attr_ops = {
328	.show	= ext4_attr_show,
329	.store	= ext4_attr_store,
330};
331
332static struct kobj_type ext4_sb_ktype = {
333	.default_attrs	= ext4_attrs,
334	.sysfs_ops	= &ext4_attr_ops,
335	.release	= ext4_sb_release,
336};
337
338static struct kobj_type ext4_ktype = {
339	.sysfs_ops	= &ext4_attr_ops,
340};
341
342static struct kset ext4_kset = {
343	.kobj   = {.ktype = &ext4_ktype},
344};
345
346static struct kobj_type ext4_feat_ktype = {
347	.default_attrs	= ext4_feat_attrs,
348	.sysfs_ops	= &ext4_attr_ops,
349};
350
351static struct kobject ext4_feat = {
352	.kset	= &ext4_kset,
353};
354
355#define PROC_FILE_SHOW_DEFN(name) \
356static int name##_open(struct inode *inode, struct file *file) \
357{ \
358	return single_open(file, ext4_seq_##name##_show, PDE_DATA(inode)); \
359} \
360\
361static const struct file_operations ext4_seq_##name##_fops = { \
362	.owner		= THIS_MODULE, \
363	.open		= name##_open, \
364	.read		= seq_read, \
365	.llseek		= seq_lseek, \
366	.release	= single_release, \
367}
368
369#define PROC_FILE_LIST(name) \
370	{ __stringify(name), &ext4_seq_##name##_fops }
371
372PROC_FILE_SHOW_DEFN(es_shrinker_info);
373PROC_FILE_SHOW_DEFN(options);
374
375static struct ext4_proc_files {
376	const char *name;
377	const struct file_operations *fops;
378} proc_files[] = {
379	PROC_FILE_LIST(options),
380	PROC_FILE_LIST(es_shrinker_info),
381	PROC_FILE_LIST(mb_groups),
382	{ NULL, NULL },
383};
384
385int ext4_register_sysfs(struct super_block *sb)
386{
387	struct ext4_sb_info *sbi = EXT4_SB(sb);
388	struct ext4_proc_files *p;
389	int err;
390
391	sbi->s_kobj.kset = &ext4_kset;
392	init_completion(&sbi->s_kobj_unregister);
393	err = kobject_init_and_add(&sbi->s_kobj, &ext4_sb_ktype, NULL,
394				   "%s", sb->s_id);
395	if (err)
396		return err;
397
398	if (ext4_proc_root)
399		sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
400
401	if (sbi->s_proc) {
402		for (p = proc_files; p->name; p++)
403			proc_create_data(p->name, S_IRUGO, sbi->s_proc,
404					 p->fops, sb);
405	}
406	return 0;
407}
408
409void ext4_unregister_sysfs(struct super_block *sb)
410{
411	struct ext4_sb_info *sbi = EXT4_SB(sb);
412	struct ext4_proc_files *p;
413
414	if (sbi->s_proc) {
415		for (p = proc_files; p->name; p++)
416			remove_proc_entry(p->name, sbi->s_proc);
417		remove_proc_entry(sb->s_id, ext4_proc_root);
418	}
419	kobject_del(&sbi->s_kobj);
420}
421
422int __init ext4_init_sysfs(void)
423{
424	int ret;
425
426	kobject_set_name(&ext4_kset.kobj, "ext4");
427	ext4_kset.kobj.parent = fs_kobj;
428	ret = kset_register(&ext4_kset);
429	if (ret)
430		return ret;
431
432	ret = kobject_init_and_add(&ext4_feat, &ext4_feat_ktype,
433				   NULL, "features");
434	if (ret)
435		kset_unregister(&ext4_kset);
436	else
437		ext4_proc_root = proc_mkdir(proc_dirname, NULL);
438	return ret;
439}
440
441void ext4_exit_sysfs(void)
442{
443	kobject_put(&ext4_feat);
444	kset_unregister(&ext4_kset);
445	remove_proc_entry(proc_dirname, NULL);
446	ext4_proc_root = NULL;
447}
448
449