[go: nahoru, domu]
1/*
2 * Assorted bcache debug code
3 *
4 * Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com>
5 * Copyright 2012 Google, Inc.
6 */
7
8#include "bcache.h"
9#include "btree.h"
10#include "debug.h"
11#include "extents.h"
12
13#include <linux/console.h>
14#include <linux/debugfs.h>
15#include <linux/module.h>
16#include <linux/random.h>
17#include <linux/seq_file.h>
18
19static struct dentry *debug;
20
21#ifdef CONFIG_BCACHE_DEBUG
22
23#define for_each_written_bset(b, start, i)				\
24	for (i = (start);						\
25	     (void *) i < (void *) (start) + (KEY_SIZE(&b->key) << 9) &&\
26	     i->seq == (start)->seq;					\
27	     i = (void *) i + set_blocks(i, block_bytes(b->c)) *	\
28		 block_bytes(b->c))
29
30void bch_btree_verify(struct btree *b)
31{
32	struct btree *v = b->c->verify_data;
33	struct bset *ondisk, *sorted, *inmemory;
34	struct bio *bio;
35
36	if (!b->c->verify || !b->c->verify_ondisk)
37		return;
38
39	down(&b->io_mutex);
40	mutex_lock(&b->c->verify_lock);
41
42	ondisk = b->c->verify_ondisk;
43	sorted = b->c->verify_data->keys.set->data;
44	inmemory = b->keys.set->data;
45
46	bkey_copy(&v->key, &b->key);
47	v->written = 0;
48	v->level = b->level;
49	v->keys.ops = b->keys.ops;
50
51	bio = bch_bbio_alloc(b->c);
52	bio->bi_bdev		= PTR_CACHE(b->c, &b->key, 0)->bdev;
53	bio->bi_iter.bi_sector	= PTR_OFFSET(&b->key, 0);
54	bio->bi_iter.bi_size	= KEY_SIZE(&v->key) << 9;
55	bch_bio_map(bio, sorted);
56
57	submit_bio_wait(REQ_META|READ_SYNC, bio);
58	bch_bbio_free(bio, b->c);
59
60	memcpy(ondisk, sorted, KEY_SIZE(&v->key) << 9);
61
62	bch_btree_node_read_done(v);
63	sorted = v->keys.set->data;
64
65	if (inmemory->keys != sorted->keys ||
66	    memcmp(inmemory->start,
67		   sorted->start,
68		   (void *) bset_bkey_last(inmemory) - (void *) inmemory->start)) {
69		struct bset *i;
70		unsigned j;
71
72		console_lock();
73
74		printk(KERN_ERR "*** in memory:\n");
75		bch_dump_bset(&b->keys, inmemory, 0);
76
77		printk(KERN_ERR "*** read back in:\n");
78		bch_dump_bset(&v->keys, sorted, 0);
79
80		for_each_written_bset(b, ondisk, i) {
81			unsigned block = ((void *) i - (void *) ondisk) /
82				block_bytes(b->c);
83
84			printk(KERN_ERR "*** on disk block %u:\n", block);
85			bch_dump_bset(&b->keys, i, block);
86		}
87
88		printk(KERN_ERR "*** block %zu not written\n",
89		       ((void *) i - (void *) ondisk) / block_bytes(b->c));
90
91		for (j = 0; j < inmemory->keys; j++)
92			if (inmemory->d[j] != sorted->d[j])
93				break;
94
95		printk(KERN_ERR "b->written %u\n", b->written);
96
97		console_unlock();
98		panic("verify failed at %u\n", j);
99	}
100
101	mutex_unlock(&b->c->verify_lock);
102	up(&b->io_mutex);
103}
104
105void bch_data_verify(struct cached_dev *dc, struct bio *bio)
106{
107	char name[BDEVNAME_SIZE];
108	struct bio *check;
109	struct bio_vec bv, *bv2;
110	struct bvec_iter iter;
111	int i;
112
113	check = bio_clone(bio, GFP_NOIO);
114	if (!check)
115		return;
116
117	if (bio_alloc_pages(check, GFP_NOIO))
118		goto out_put;
119
120	submit_bio_wait(READ_SYNC, check);
121
122	bio_for_each_segment(bv, bio, iter) {
123		void *p1 = kmap_atomic(bv.bv_page);
124		void *p2 = page_address(check->bi_io_vec[iter.bi_idx].bv_page);
125
126		cache_set_err_on(memcmp(p1 + bv.bv_offset,
127					p2 + bv.bv_offset,
128					bv.bv_len),
129				 dc->disk.c,
130				 "verify failed at dev %s sector %llu",
131				 bdevname(dc->bdev, name),
132				 (uint64_t) bio->bi_iter.bi_sector);
133
134		kunmap_atomic(p1);
135	}
136
137	bio_for_each_segment_all(bv2, check, i)
138		__free_page(bv2->bv_page);
139out_put:
140	bio_put(check);
141}
142
143#endif
144
145#ifdef CONFIG_DEBUG_FS
146
147/* XXX: cache set refcounting */
148
149struct dump_iterator {
150	char			buf[PAGE_SIZE];
151	size_t			bytes;
152	struct cache_set	*c;
153	struct keybuf		keys;
154};
155
156static bool dump_pred(struct keybuf *buf, struct bkey *k)
157{
158	return true;
159}
160
161static ssize_t bch_dump_read(struct file *file, char __user *buf,
162			     size_t size, loff_t *ppos)
163{
164	struct dump_iterator *i = file->private_data;
165	ssize_t ret = 0;
166	char kbuf[80];
167
168	while (size) {
169		struct keybuf_key *w;
170		unsigned bytes = min(i->bytes, size);
171
172		int err = copy_to_user(buf, i->buf, bytes);
173		if (err)
174			return err;
175
176		ret	 += bytes;
177		buf	 += bytes;
178		size	 -= bytes;
179		i->bytes -= bytes;
180		memmove(i->buf, i->buf + bytes, i->bytes);
181
182		if (i->bytes)
183			break;
184
185		w = bch_keybuf_next_rescan(i->c, &i->keys, &MAX_KEY, dump_pred);
186		if (!w)
187			break;
188
189		bch_extent_to_text(kbuf, sizeof(kbuf), &w->key);
190		i->bytes = snprintf(i->buf, PAGE_SIZE, "%s\n", kbuf);
191		bch_keybuf_del(&i->keys, w);
192	}
193
194	return ret;
195}
196
197static int bch_dump_open(struct inode *inode, struct file *file)
198{
199	struct cache_set *c = inode->i_private;
200	struct dump_iterator *i;
201
202	i = kzalloc(sizeof(struct dump_iterator), GFP_KERNEL);
203	if (!i)
204		return -ENOMEM;
205
206	file->private_data = i;
207	i->c = c;
208	bch_keybuf_init(&i->keys);
209	i->keys.last_scanned = KEY(0, 0, 0);
210
211	return 0;
212}
213
214static int bch_dump_release(struct inode *inode, struct file *file)
215{
216	kfree(file->private_data);
217	return 0;
218}
219
220static const struct file_operations cache_set_debug_ops = {
221	.owner		= THIS_MODULE,
222	.open		= bch_dump_open,
223	.read		= bch_dump_read,
224	.release	= bch_dump_release
225};
226
227void bch_debug_init_cache_set(struct cache_set *c)
228{
229	if (!IS_ERR_OR_NULL(debug)) {
230		char name[50];
231		snprintf(name, 50, "bcache-%pU", c->sb.set_uuid);
232
233		c->debug = debugfs_create_file(name, 0400, debug, c,
234					       &cache_set_debug_ops);
235	}
236}
237
238#endif
239
240void bch_debug_exit(void)
241{
242	if (!IS_ERR_OR_NULL(debug))
243		debugfs_remove_recursive(debug);
244}
245
246int __init bch_debug_init(struct kobject *kobj)
247{
248	int ret = 0;
249
250	debug = debugfs_create_dir("bcache", NULL);
251	return ret;
252}
253