drivers/md/bcache/debug.c

   1 /*
   2  * Assorted bcache debug code
   3  *
   4  * Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com>
   5  * Copyright 2012 Google, Inc.
   6  */
   7
   8 #include "bcache.h"
   9 #include "btree.h"
  10 #include "debug.h"
  11 #include "extents.h"
  12
  13 #include <linux/console.h>
  14 #include <linux/debugfs.h>
  15 #include <linux/module.h>
  16 #include <linux/random.h>
  17 #include <linux/seq_file.h>
  18
  19 static struct dentry *debug;
  20
  21 #ifdef CONFIG_BCACHE_DEBUG
  22
  23 #define for_each_written_bset(b, start, i)                              \
  24         for (i = (start);                                               \
  25              (void *) i < (void *) (start) + (KEY_SIZE(&b->key) << 9) &&\
  26              i->seq == (start)->seq;                                    \
  27              i = (void *) i + set_blocks(i, block_bytes(b->c)) *        \
  28                  block_bytes(b->c))
  29
  30 void bch_btree_verify(struct btree *b)
  31 {
  32         struct btree *v = b->c->verify_data;
  33         struct bset *ondisk, *sorted, *inmemory;
  34         struct bio *bio;
  35
  36         if (!b->c->verify || !b->c->verify_ondisk)
  37                 return;
  38
  39         down(&b->io_mutex);
  40         mutex_lock(&b->c->verify_lock);
  41
  42         ondisk = b->c->verify_ondisk;
  43         sorted = b->c->verify_data->keys.set->data;
  44         inmemory = b->keys.set->data;
  45
  46         bkey_copy(&v->key, &b->key);
  47         v->written = 0;
  48         v->level = b->level;
  49         v->keys.ops = b->keys.ops;
  50
  51         bio = bch_bbio_alloc(b->c);
  52         bio->bi_bdev            = PTR_CACHE(b->c, &b->key, 0)->bdev;
  53         bio->bi_iter.bi_sector  = PTR_OFFSET(&b->key, 0);
  54         bio->bi_iter.bi_size    = KEY_SIZE(&v->key) << 9;
  55         bio_set_op_attrs(bio, REQ_OP_READ, REQ_META|READ_SYNC);
  56         bch_bio_map(bio, sorted);
  57
  58         submit_bio_wait(bio);
  59         bch_bbio_free(bio, b->c);
  60
  61         memcpy(ondisk, sorted, KEY_SIZE(&v->key) << 9);
  62
  63         bch_btree_node_read_done(v);
  64         sorted = v->keys.set->data;
  65
  66         if (inmemory->keys != sorted->keys ||
  67             memcmp(inmemory->start,
  68                    sorted->start,
  69                    (void *) bset_bkey_last(inmemory) - (void *) inmemory->start)) {
  70                 struct bset *i;
  71                 unsigned j;
  72
  73                 console_lock();
  74
  75                 printk(KERN_ERR "*** in memory:\n");
  76                 bch_dump_bset(&b->keys, inmemory, 0);
  77
  78                 printk(KERN_ERR "*** read back in:\n");
  79                 bch_dump_bset(&v->keys, sorted, 0);
  80
  81                 for_each_written_bset(b, ondisk, i) {
  82                         unsigned block = ((void *) i - (void *) ondisk) /
  83                                 block_bytes(b->c);
  84
  85                         printk(KERN_ERR "*** on disk block %u:\n", block);
  86                         bch_dump_bset(&b->keys, i, block);
  87                 }
  88
  89                 printk(KERN_ERR "*** block %zu not written\n",
  90                        ((void *) i - (void *) ondisk) / block_bytes(b->c));
  91
  92                 for (j = 0; j < inmemory->keys; j++)
  93                         if (inmemory->d[j] != sorted->d[j])
  94                                 break;
  95
  96                 printk(KERN_ERR "b->written %u\n", b->written);
  97
  98                 console_unlock();
  99                 panic("verify failed at %u\n", j);
 100         }
 101
 102         mutex_unlock(&b->c->verify_lock);
 103         up(&b->io_mutex);
 104 }
 105
 106 void bch_data_verify(struct cached_dev *dc, struct bio *bio)
 107 {
 108         char name[BDEVNAME_SIZE];
 109         struct bio *check;
 110         struct bio_vec bv, *bv2;
 111         struct bvec_iter iter;
 112         int i;
 113
 114         check = bio_clone(bio, GFP_NOIO);
 115         if (!check)
 116                 return;
 117         bio_set_op_attrs(check, REQ_OP_READ, READ_SYNC);
 118
 119         if (bio_alloc_pages(check, GFP_NOIO))
 120                 goto out_put;
 121
 122         submit_bio_wait(check);
 123
 124         bio_for_each_segment(bv, bio, iter) {
 125                 void *p1 = kmap_atomic(bv.bv_page);
 126                 void *p2 = page_address(check->bi_io_vec[iter.bi_idx].bv_page);
 127
 128                 cache_set_err_on(memcmp(p1 + bv.bv_offset,
 129                                         p2 + bv.bv_offset,
 130                                         bv.bv_len),
 131                                  dc->disk.c,
 132                                  "verify failed at dev %s sector %llu",
 133                                  bdevname(dc->bdev, name),
 134                                  (uint64_t) bio->bi_iter.bi_sector);
 135
 136                 kunmap_atomic(p1);
 137         }
 138
 139         bio_for_each_segment_all(bv2, check, i)
 140                 __free_page(bv2->bv_page);
 141 out_put:
 142         bio_put(check);
 143 }
 144
 145 #endif
 146
 147 #ifdef CONFIG_DEBUG_FS
 148
 149 /* XXX: cache set refcounting */
 150
 151 struct dump_iterator {
 152         char                    buf[PAGE_SIZE];
 153         size_t                  bytes;
 154         struct cache_set        *c;
 155         struct keybuf           keys;
 156 };
 157
 158 static bool dump_pred(struct keybuf *buf, struct bkey *k)
 159 {
 160         return true;
 161 }
 162
 163 static ssize_t bch_dump_read(struct file *file, char __user *buf,
 164                              size_t size, loff_t *ppos)
 165 {
 166         struct dump_iterator *i = file->private_data;
 167         ssize_t ret = 0;
 168         char kbuf[80];
 169
 170         while (size) {
 171                 struct keybuf_key *w;
 172                 unsigned bytes = min(i->bytes, size);
 173
 174                 int err = copy_to_user(buf, i->buf, bytes);
 175                 if (err)
 176                         return err;
 177
 178                 ret      += bytes;
 179                 buf      += bytes;
 180                 size     -= bytes;
 181                 i->bytes -= bytes;
 182                 memmove(i->buf, i->buf + bytes, i->bytes);
 183
 184                 if (i->bytes)
 185                         break;
 186
 187                 w = bch_keybuf_next_rescan(i->c, &i->keys, &MAX_KEY, dump_pred);
 188                 if (!w)
 189                         break;
 190
 191                 bch_extent_to_text(kbuf, sizeof(kbuf), &w->key);
 192                 i->bytes = snprintf(i->buf, PAGE_SIZE, "%s\n", kbuf);
 193                 bch_keybuf_del(&i->keys, w);
 194         }
 195
 196         return ret;
 197 }
 198
 199 static int bch_dump_open(struct inode *inode, struct file *file)
 200 {
 201         struct cache_set *c = inode->i_private;
 202         struct dump_iterator *i;
 203
 204         i = kzalloc(sizeof(struct dump_iterator), GFP_KERNEL);
 205         if (!i)
 206                 return -ENOMEM;
 207
 208         file->private_data = i;
 209         i->c = c;
 210         bch_keybuf_init(&i->keys);
 211         i->keys.last_scanned = KEY(0, 0, 0);
 212
 213         return 0;
 214 }
 215
 216 static int bch_dump_release(struct inode *inode, struct file *file)
 217 {
 218         kfree(file->private_data);
 219         return 0;
 220 }
 221
 222 static const struct file_operations cache_set_debug_ops = {
 223         .owner          = THIS_MODULE,
 224         .open           = bch_dump_open,
 225         .read           = bch_dump_read,
 226         .release        = bch_dump_release
 227 };
 228
 229 void bch_debug_init_cache_set(struct cache_set *c)
 230 {
 231         if (!IS_ERR_OR_NULL(debug)) {
 232                 char name[50];
 233                 snprintf(name, 50, "bcache-%pU", c->sb.set_uuid);
 234
 235                 c->debug = debugfs_create_file(name, 0400, debug, c,
 236                                                &cache_set_debug_ops);
 237         }
 238 }
 239
 240 #endif
 241
 242 void bch_debug_exit(void)
 243 {
 244         if (!IS_ERR_OR_NULL(debug))
 245                 debugfs_remove_recursive(debug);
 246 }
 247
 248 int __init bch_debug_init(struct kobject *kobj)
 249 {
 250         int ret = 0;
 251
 252         debug = debugfs_create_dir("bcache", NULL);
 253         return ret;
 254 }