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 static struct dentry *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) - (void *) inmemory->start)) {
  71                 struct bset *i;
  72                 unsigned j;
  73
  74                 console_lock();
  75
  76                 printk(KERN_ERR "*** in memory:\n");
  77                 bch_dump_bset(&b->keys, inmemory, 0);
  78
  79                 printk(KERN_ERR "*** read back in:\n");
  80                 bch_dump_bset(&v->keys, sorted, 0);
  81
  82                 for_each_written_bset(b, ondisk, i) {
  83                         unsigned block = ((void *) i - (void *) ondisk) /
  84                                 block_bytes(b->c);
  85
  86                         printk(KERN_ERR "*** on disk block %u:\n", block);
  87                         bch_dump_bset(&b->keys, i, block);
  88                 }
  89
  90                 printk(KERN_ERR "*** block %zu not written\n",
  91                        ((void *) i - (void *) ondisk) / block_bytes(b->c));
  92
  93                 for (j = 0; j < inmemory->keys; j++)
  94                         if (inmemory->d[j] != sorted->d[j])
  95                                 break;
  96
  97                 printk(KERN_ERR "b->written %u\n", b->written);
  98
  99                 console_unlock();
 100                 panic("verify failed at %u\n", j);
 101         }
 102
 103         mutex_unlock(&b->c->verify_lock);
 104         up(&b->io_mutex);
 105 }
 106
 107 void bch_data_verify(struct cached_dev *dc, struct bio *bio)
 108 {
 109         char name[BDEVNAME_SIZE];
 110         struct bio *check;
 111         struct bio_vec bv, cbv;
 112         struct bvec_iter iter, citer = { 0 };
 113
 114         check = bio_clone_kmalloc(bio, GFP_NOIO);
 115         if (!check)
 116                 return;
 117         check->bi_opf = REQ_OP_READ;
 118
 119         if (bch_bio_alloc_pages(check, GFP_NOIO))
 120                 goto out_put;
 121
 122         submit_bio_wait(check);
 123
 124         citer.bi_size = UINT_MAX;
 125         bio_for_each_segment(bv, bio, iter) {
 126                 void *p1 = kmap_atomic(bv.bv_page);
 127                 void *p2;
 128
 129                 cbv = bio_iter_iovec(check, citer);
 130                 p2 = page_address(cbv.bv_page);
 131
 132                 cache_set_err_on(memcmp(p1 + bv.bv_offset,
 133                                         p2 + bv.bv_offset,
 134                                         bv.bv_len),
 135                                  dc->disk.c,
 136                                  "verify failed at dev %s sector %llu",
 137                                  bdevname(dc->bdev, name),
 138                                  (uint64_t) bio->bi_iter.bi_sector);
 139
 140                 kunmap_atomic(p1);
 141                 bio_advance_iter(check, &citer, bv.bv_len);
 142         }
 143
 144         bio_free_pages(check);
 145 out_put:
 146         bio_put(check);
 147 }
 148
 149 #endif
 150
 151 #ifdef CONFIG_DEBUG_FS
 152
 153 /* XXX: cache set refcounting */
 154
 155 struct dump_iterator {
 156         char                    buf[PAGE_SIZE];
 157         size_t                  bytes;
 158         struct cache_set        *c;
 159         struct keybuf           keys;
 160 };
 161
 162 static bool dump_pred(struct keybuf *buf, struct bkey *k)
 163 {
 164         return true;
 165 }
 166
 167 static ssize_t bch_dump_read(struct file *file, char __user *buf,
 168                              size_t size, loff_t *ppos)
 169 {
 170         struct dump_iterator *i = file->private_data;
 171         ssize_t ret = 0;
 172         char kbuf[80];
 173
 174         while (size) {
 175                 struct keybuf_key *w;
 176                 unsigned bytes = min(i->bytes, size);
 177
 178                 int err = copy_to_user(buf, i->buf, bytes);
 179                 if (err)
 180                         return err;
 181
 182                 ret      += bytes;
 183                 buf      += bytes;
 184                 size     -= bytes;
 185                 i->bytes -= bytes;
 186                 memmove(i->buf, i->buf + bytes, i->bytes);
 187
 188                 if (i->bytes)
 189                         break;
 190
 191                 w = bch_keybuf_next_rescan(i->c, &i->keys, &MAX_KEY, dump_pred);
 192                 if (!w)
 193                         break;
 194
 195                 bch_extent_to_text(kbuf, sizeof(kbuf), &w->key);
 196                 i->bytes = snprintf(i->buf, PAGE_SIZE, "%s\n", kbuf);
 197                 bch_keybuf_del(&i->keys, w);
 198         }
 199
 200         return ret;
 201 }
 202
 203 static int bch_dump_open(struct inode *inode, struct file *file)
 204 {
 205         struct cache_set *c = inode->i_private;
 206         struct dump_iterator *i;
 207
 208         i = kzalloc(sizeof(struct dump_iterator), GFP_KERNEL);
 209         if (!i)
 210                 return -ENOMEM;
 211
 212         file->private_data = i;
 213         i->c = c;
 214         bch_keybuf_init(&i->keys);
 215         i->keys.last_scanned = KEY(0, 0, 0);
 216
 217         return 0;
 218 }
 219
 220 static int bch_dump_release(struct inode *inode, struct file *file)
 221 {
 222         kfree(file->private_data);
 223         return 0;
 224 }
 225
 226 static const struct file_operations cache_set_debug_ops = {
 227         .owner          = THIS_MODULE,
 228         .open           = bch_dump_open,
 229         .read           = bch_dump_read,
 230         .release        = bch_dump_release
 231 };
 232
 233 void bch_debug_init_cache_set(struct cache_set *c)
 234 {
 235         if (!IS_ERR_OR_NULL(debug)) {
 236                 char name[50];
 237                 snprintf(name, 50, "bcache-%pU", c->sb.set_uuid);
 238
 239                 c->debug = debugfs_create_file(name, 0400, debug, c,
 240                                                &cache_set_debug_ops);
 241         }
 242 }
 243
 244 #endif
 245
 246 void bch_debug_exit(void)
 247 {
 248         if (!IS_ERR_OR_NULL(debug))
 249                 debugfs_remove_recursive(debug);
 250 }
 251
 252 int __init bch_debug_init(struct kobject *kobj)
 253 {
 254         if (!IS_ENABLED(CONFIG_DEBUG_FS))
 255                 return 0;
 256
 257         debug = debugfs_create_dir("bcache", NULL);
 258
 259         return IS_ERR_OR_NULL(debug);
 260 }