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 
bch_btree_verify(struct btree * b)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 
bch_data_verify(struct cached_dev * dc,struct bio * bio)108 void bch_data_verify(struct cached_dev *dc, struct bio *bio)
109 {
110 	unsigned int nr_segs = bio_segments(bio);
111 	struct bio *check;
112 	struct bio_vec bv, cbv;
113 	struct bvec_iter iter, citer = { 0 };
114 
115 	check = bio_kmalloc(nr_segs, GFP_NOIO);
116 	if (!check)
117 		return;
118 	bio_init(check, bio->bi_bdev, check->bi_inline_vecs, nr_segs,
119 		 REQ_OP_READ);
120 	check->bi_iter.bi_sector = bio->bi_iter.bi_sector;
121 	check->bi_iter.bi_size = bio->bi_iter.bi_size;
122 
123 	bch_bio_map(check, NULL);
124 	if (bch_bio_alloc_pages(check, GFP_NOIO))
125 		goto out_put;
126 
127 	submit_bio_wait(check);
128 
129 	citer.bi_size = UINT_MAX;
130 	bio_for_each_segment(bv, bio, iter) {
131 		void *p1 = bvec_kmap_local(&bv);
132 		void *p2;
133 
134 		cbv = bio_iter_iovec(check, citer);
135 		p2 = bvec_kmap_local(&cbv);
136 
137 		cache_set_err_on(memcmp(p1, p2, bv.bv_len),
138 				 dc->disk.c,
139 				 "verify failed at dev %pg sector %llu",
140 				 dc->bdev,
141 				 (uint64_t) bio->bi_iter.bi_sector);
142 
143 		kunmap_local(p2);
144 		kunmap_local(p1);
145 		bio_advance_iter(check, &citer, bv.bv_len);
146 	}
147 
148 	bio_free_pages(check);
149 out_put:
150 	bio_uninit(check);
151 	kfree(check);
152 }
153 
154 #endif
155 
156 #ifdef CONFIG_DEBUG_FS
157 
158 /* XXX: cache set refcounting */
159 
160 struct dump_iterator {
161 	char			buf[PAGE_SIZE];
162 	size_t			bytes;
163 	struct cache_set	*c;
164 	struct keybuf		keys;
165 };
166 
dump_pred(struct keybuf * buf,struct bkey * k)167 static bool dump_pred(struct keybuf *buf, struct bkey *k)
168 {
169 	return true;
170 }
171 
bch_dump_read(struct file * file,char __user * buf,size_t size,loff_t * ppos)172 static ssize_t bch_dump_read(struct file *file, char __user *buf,
173 			     size_t size, loff_t *ppos)
174 {
175 	struct dump_iterator *i = file->private_data;
176 	ssize_t ret = 0;
177 	char kbuf[80];
178 
179 	while (size) {
180 		struct keybuf_key *w;
181 		unsigned int bytes = min(i->bytes, size);
182 
183 		if (copy_to_user(buf, i->buf, bytes))
184 			return -EFAULT;
185 
186 		ret	 += bytes;
187 		buf	 += bytes;
188 		size	 -= bytes;
189 		i->bytes -= bytes;
190 		memmove(i->buf, i->buf + bytes, i->bytes);
191 
192 		if (i->bytes)
193 			break;
194 
195 		w = bch_keybuf_next_rescan(i->c, &i->keys, &MAX_KEY, dump_pred);
196 		if (!w)
197 			break;
198 
199 		bch_extent_to_text(kbuf, sizeof(kbuf), &w->key);
200 		i->bytes = snprintf(i->buf, PAGE_SIZE, "%s\n", kbuf);
201 		bch_keybuf_del(&i->keys, w);
202 	}
203 
204 	return ret;
205 }
206 
bch_dump_open(struct inode * inode,struct file * file)207 static int bch_dump_open(struct inode *inode, struct file *file)
208 {
209 	struct cache_set *c = inode->i_private;
210 	struct dump_iterator *i;
211 
212 	i = kzalloc(sizeof(struct dump_iterator), GFP_KERNEL);
213 	if (!i)
214 		return -ENOMEM;
215 
216 	file->private_data = i;
217 	i->c = c;
218 	bch_keybuf_init(&i->keys);
219 	i->keys.last_scanned = KEY(0, 0, 0);
220 
221 	return 0;
222 }
223 
bch_dump_release(struct inode * inode,struct file * file)224 static int bch_dump_release(struct inode *inode, struct file *file)
225 {
226 	kfree(file->private_data);
227 	return 0;
228 }
229 
230 static const struct file_operations cache_set_debug_ops = {
231 	.owner		= THIS_MODULE,
232 	.open		= bch_dump_open,
233 	.read		= bch_dump_read,
234 	.release	= bch_dump_release
235 };
236 
bch_debug_init_cache_set(struct cache_set * c)237 void bch_debug_init_cache_set(struct cache_set *c)
238 {
239 	if (!IS_ERR_OR_NULL(bcache_debug)) {
240 		char name[50];
241 
242 		snprintf(name, 50, "bcache-%pU", c->set_uuid);
243 		c->debug = debugfs_create_file(name, 0400, bcache_debug, c,
244 					       &cache_set_debug_ops);
245 	}
246 }
247 
248 #endif
249 
bch_debug_exit(void)250 void bch_debug_exit(void)
251 {
252 	debugfs_remove_recursive(bcache_debug);
253 }
254 
bch_debug_init(void)255 void __init bch_debug_init(void)
256 {
257 	/*
258 	 * it is unnecessary to check return value of
259 	 * debugfs_create_file(), we should not care
260 	 * about this.
261 	 */
262 	bcache_debug = debugfs_create_dir("bcache", NULL);
263 }
264