xref: /openbmc/linux/drivers/md/bcache/debug.c (revision eb3fcf00)
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 
19 static 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 
30 void 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 
105 void 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);
139 out_put:
140 	bio_put(check);
141 }
142 
143 #endif
144 
145 #ifdef CONFIG_DEBUG_FS
146 
147 /* XXX: cache set refcounting */
148 
149 struct dump_iterator {
150 	char			buf[PAGE_SIZE];
151 	size_t			bytes;
152 	struct cache_set	*c;
153 	struct keybuf		keys;
154 };
155 
156 static bool dump_pred(struct keybuf *buf, struct bkey *k)
157 {
158 	return true;
159 }
160 
161 static 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 
197 static 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 
214 static int bch_dump_release(struct inode *inode, struct file *file)
215 {
216 	kfree(file->private_data);
217 	return 0;
218 }
219 
220 static 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 
227 void 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 
240 void bch_debug_exit(void)
241 {
242 	if (!IS_ERR_OR_NULL(debug))
243 		debugfs_remove_recursive(debug);
244 }
245 
246 int __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