GNU Linux-libre 4.19.314-gnu1
[releases.git] / drivers / md / bcache / debug.c
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)) *        \
29                  block_bytes(b->c))
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, PTR_CACHE(b->c, &b->key, 0)->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);
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));
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         check->bi_disk = bio->bi_disk;
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 = kmap_atomic(bv.bv_page);
131                 void *p2;
132
133                 cbv = bio_iter_iovec(check, citer);
134                 p2 = page_address(cbv.bv_page);
135
136                 cache_set_err_on(memcmp(p1 + bv.bv_offset,
137                                         p2 + bv.bv_offset,
138                                         bv.bv_len),
139                                  dc->disk.c,
140                                  "verify failed at dev %s sector %llu",
141                                  dc->backing_dev_name,
142                                  (uint64_t) bio->bi_iter.bi_sector);
143
144                 kunmap_atomic(p1);
145                 bio_advance_iter(check, &citer, bv.bv_len);
146         }
147
148         bio_free_pages(check);
149 out_put:
150         bio_put(check);
151 }
152
153 #endif
154
155 #ifdef CONFIG_DEBUG_FS
156
157 /* XXX: cache set refcounting */
158
159 struct dump_iterator {
160         char                    buf[PAGE_SIZE];
161         size_t                  bytes;
162         struct cache_set        *c;
163         struct keybuf           keys;
164 };
165
166 static bool dump_pred(struct keybuf *buf, struct bkey *k)
167 {
168         return true;
169 }
170
171 static ssize_t bch_dump_read(struct file *file, char __user *buf,
172                              size_t size, loff_t *ppos)
173 {
174         struct dump_iterator *i = file->private_data;
175         ssize_t ret = 0;
176         char kbuf[80];
177
178         while (size) {
179                 struct keybuf_key *w;
180                 unsigned int bytes = min(i->bytes, size);
181
182                 if (copy_to_user(buf, i->buf, bytes))
183                         return -EFAULT;
184
185                 ret      += bytes;
186                 buf      += bytes;
187                 size     -= bytes;
188                 i->bytes -= bytes;
189                 memmove(i->buf, i->buf + bytes, i->bytes);
190
191                 if (i->bytes)
192                         break;
193
194                 w = bch_keybuf_next_rescan(i->c, &i->keys, &MAX_KEY, dump_pred);
195                 if (!w)
196                         break;
197
198                 bch_extent_to_text(kbuf, sizeof(kbuf), &w->key);
199                 i->bytes = snprintf(i->buf, PAGE_SIZE, "%s\n", kbuf);
200                 bch_keybuf_del(&i->keys, w);
201         }
202
203         return ret;
204 }
205
206 static int bch_dump_open(struct inode *inode, struct file *file)
207 {
208         struct cache_set *c = inode->i_private;
209         struct dump_iterator *i;
210
211         i = kzalloc(sizeof(struct dump_iterator), GFP_KERNEL);
212         if (!i)
213                 return -ENOMEM;
214
215         file->private_data = i;
216         i->c = c;
217         bch_keybuf_init(&i->keys);
218         i->keys.last_scanned = KEY(0, 0, 0);
219
220         return 0;
221 }
222
223 static int bch_dump_release(struct inode *inode, struct file *file)
224 {
225         kfree(file->private_data);
226         return 0;
227 }
228
229 static const struct file_operations cache_set_debug_ops = {
230         .owner          = THIS_MODULE,
231         .open           = bch_dump_open,
232         .read           = bch_dump_read,
233         .release        = bch_dump_release
234 };
235
236 void bch_debug_init_cache_set(struct cache_set *c)
237 {
238         if (!IS_ERR_OR_NULL(bcache_debug)) {
239                 char name[50];
240
241                 snprintf(name, 50, "bcache-%pU", c->sb.set_uuid);
242                 c->debug = debugfs_create_file(name, 0400, bcache_debug, c,
243                                                &cache_set_debug_ops);
244         }
245 }
246
247 #endif
248
249 void bch_debug_exit(void)
250 {
251         debugfs_remove_recursive(bcache_debug);
252 }
253
254 void __init bch_debug_init(struct kobject *kobj)
255 {
256         /*
257          * it is unnecessary to check return value of
258          * debugfs_create_file(), we should not care
259          * about this.
260          */
261         bcache_debug = debugfs_create_dir("bcache", NULL);
262 }