xref: /openbmc/linux/drivers/md/bcache/debug.c (revision 09717af7)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Assorted bcache debug code
4  *
5  * Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com>
6  * Copyright 2012 Google, Inc.
7  */
8 
9 #include "bcache.h"
10 #include "btree.h"
11 #include "debug.h"
12 #include "extents.h"
13 
14 #include <linux/console.h>
15 #include <linux/debugfs.h>
16 #include <linux/module.h>
17 #include <linux/random.h>
18 #include <linux/seq_file.h>
19 
20 struct dentry *bcache_debug;
21 
22 #ifdef CONFIG_BCACHE_DEBUG
23 
24 #define for_each_written_bset(b, start, i)				\
25 	for (i = (start);						\
26 	     (void *) i < (void *) (start) + (KEY_SIZE(&b->key) << 9) &&\
27 	     i->seq == (start)->seq;					\
28 	     i = (void *) i + set_blocks(i, block_bytes(b->c->cache)) *	\
29 		 block_bytes(b->c->cache))
30 
31 void bch_btree_verify(struct btree *b)
32 {
33 	struct btree *v = b->c->verify_data;
34 	struct bset *ondisk, *sorted, *inmemory;
35 	struct bio *bio;
36 
37 	if (!b->c->verify || !b->c->verify_ondisk)
38 		return;
39 
40 	down(&b->io_mutex);
41 	mutex_lock(&b->c->verify_lock);
42 
43 	ondisk = b->c->verify_ondisk;
44 	sorted = b->c->verify_data->keys.set->data;
45 	inmemory = b->keys.set->data;
46 
47 	bkey_copy(&v->key, &b->key);
48 	v->written = 0;
49 	v->level = b->level;
50 	v->keys.ops = b->keys.ops;
51 
52 	bio = bch_bbio_alloc(b->c);
53 	bio_set_dev(bio, b->c->cache->bdev);
54 	bio->bi_iter.bi_sector	= PTR_OFFSET(&b->key, 0);
55 	bio->bi_iter.bi_size	= KEY_SIZE(&v->key) << 9;
56 	bio->bi_opf		= REQ_OP_READ | REQ_META;
57 	bch_bio_map(bio, sorted);
58 
59 	submit_bio_wait(bio);
60 	bch_bbio_free(bio, b->c);
61 
62 	memcpy(ondisk, sorted, KEY_SIZE(&v->key) << 9);
63 
64 	bch_btree_node_read_done(v);
65 	sorted = v->keys.set->data;
66 
67 	if (inmemory->keys != sorted->keys ||
68 	    memcmp(inmemory->start,
69 		   sorted->start,
70 		   (void *) bset_bkey_last(inmemory) -
71 		   (void *) inmemory->start)) {
72 		struct bset *i;
73 		unsigned int j;
74 
75 		console_lock();
76 
77 		pr_err("*** in memory:\n");
78 		bch_dump_bset(&b->keys, inmemory, 0);
79 
80 		pr_err("*** read back in:\n");
81 		bch_dump_bset(&v->keys, sorted, 0);
82 
83 		for_each_written_bset(b, ondisk, i) {
84 			unsigned int block = ((void *) i - (void *) ondisk) /
85 				block_bytes(b->c->cache);
86 
87 			pr_err("*** on disk block %u:\n", block);
88 			bch_dump_bset(&b->keys, i, block);
89 		}
90 
91 		pr_err("*** block %zu not written\n",
92 		       ((void *) i - (void *) ondisk) / block_bytes(b->c->cache));
93 
94 		for (j = 0; j < inmemory->keys; j++)
95 			if (inmemory->d[j] != sorted->d[j])
96 				break;
97 
98 		pr_err("b->written %u\n", b->written);
99 
100 		console_unlock();
101 		panic("verify failed at %u\n", j);
102 	}
103 
104 	mutex_unlock(&b->c->verify_lock);
105 	up(&b->io_mutex);
106 }
107 
108 void bch_data_verify(struct cached_dev *dc, struct bio *bio)
109 {
110 	struct bio *check;
111 	struct bio_vec bv, cbv;
112 	struct bvec_iter iter, citer = { 0 };
113 
114 	check = bio_kmalloc(GFP_NOIO, bio_segments(bio));
115 	if (!check)
116 		return;
117 	bio_set_dev(check, bio->bi_bdev);
118 	check->bi_opf = REQ_OP_READ;
119 	check->bi_iter.bi_sector = bio->bi_iter.bi_sector;
120 	check->bi_iter.bi_size = bio->bi_iter.bi_size;
121 
122 	bch_bio_map(check, NULL);
123 	if (bch_bio_alloc_pages(check, GFP_NOIO))
124 		goto out_put;
125 
126 	submit_bio_wait(check);
127 
128 	citer.bi_size = UINT_MAX;
129 	bio_for_each_segment(bv, bio, iter) {
130 		void *p1 = bvec_kmap_local(&bv);
131 		void *p2;
132 
133 		cbv = bio_iter_iovec(check, citer);
134 		p2 = bvec_kmap_local(&cbv);
135 
136 		cache_set_err_on(memcmp(p1, p2, bv.bv_len),
137 				 dc->disk.c,
138 				 "verify failed at dev %pg sector %llu",
139 				 dc->bdev,
140 				 (uint64_t) bio->bi_iter.bi_sector);
141 
142 		kunmap_local(p2);
143 		kunmap_local(p1);
144 		bio_advance_iter(check, &citer, bv.bv_len);
145 	}
146 
147 	bio_free_pages(check);
148 out_put:
149 	bio_put(check);
150 }
151 
152 #endif
153 
154 #ifdef CONFIG_DEBUG_FS
155 
156 /* XXX: cache set refcounting */
157 
158 struct dump_iterator {
159 	char			buf[PAGE_SIZE];
160 	size_t			bytes;
161 	struct cache_set	*c;
162 	struct keybuf		keys;
163 };
164 
165 static bool dump_pred(struct keybuf *buf, struct bkey *k)
166 {
167 	return true;
168 }
169 
170 static ssize_t bch_dump_read(struct file *file, char __user *buf,
171 			     size_t size, loff_t *ppos)
172 {
173 	struct dump_iterator *i = file->private_data;
174 	ssize_t ret = 0;
175 	char kbuf[80];
176 
177 	while (size) {
178 		struct keybuf_key *w;
179 		unsigned int bytes = min(i->bytes, size);
180 
181 		if (copy_to_user(buf, i->buf, bytes))
182 			return -EFAULT;
183 
184 		ret	 += bytes;
185 		buf	 += bytes;
186 		size	 -= bytes;
187 		i->bytes -= bytes;
188 		memmove(i->buf, i->buf + bytes, i->bytes);
189 
190 		if (i->bytes)
191 			break;
192 
193 		w = bch_keybuf_next_rescan(i->c, &i->keys, &MAX_KEY, dump_pred);
194 		if (!w)
195 			break;
196 
197 		bch_extent_to_text(kbuf, sizeof(kbuf), &w->key);
198 		i->bytes = snprintf(i->buf, PAGE_SIZE, "%s\n", kbuf);
199 		bch_keybuf_del(&i->keys, w);
200 	}
201 
202 	return ret;
203 }
204 
205 static int bch_dump_open(struct inode *inode, struct file *file)
206 {
207 	struct cache_set *c = inode->i_private;
208 	struct dump_iterator *i;
209 
210 	i = kzalloc(sizeof(struct dump_iterator), GFP_KERNEL);
211 	if (!i)
212 		return -ENOMEM;
213 
214 	file->private_data = i;
215 	i->c = c;
216 	bch_keybuf_init(&i->keys);
217 	i->keys.last_scanned = KEY(0, 0, 0);
218 
219 	return 0;
220 }
221 
222 static int bch_dump_release(struct inode *inode, struct file *file)
223 {
224 	kfree(file->private_data);
225 	return 0;
226 }
227 
228 static const struct file_operations cache_set_debug_ops = {
229 	.owner		= THIS_MODULE,
230 	.open		= bch_dump_open,
231 	.read		= bch_dump_read,
232 	.release	= bch_dump_release
233 };
234 
235 void bch_debug_init_cache_set(struct cache_set *c)
236 {
237 	if (!IS_ERR_OR_NULL(bcache_debug)) {
238 		char name[50];
239 
240 		snprintf(name, 50, "bcache-%pU", c->set_uuid);
241 		c->debug = debugfs_create_file(name, 0400, bcache_debug, c,
242 					       &cache_set_debug_ops);
243 	}
244 }
245 
246 #endif
247 
248 void bch_debug_exit(void)
249 {
250 	debugfs_remove_recursive(bcache_debug);
251 }
252 
253 void __init bch_debug_init(void)
254 {
255 	/*
256 	 * it is unnecessary to check return value of
257 	 * debugfs_create_file(), we should not care
258 	 * about this.
259 	 */
260 	bcache_debug = debugfs_create_dir("bcache", NULL);
261 }
262