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->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, 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->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         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->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(void)
 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 }