linux/drivers/md/bcache/debug.c
<<
>>
Prefs
   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
  20struct 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
  31void 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
 108void 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);
 149out_put:
 150        bio_put(check);
 151}
 152
 153#endif
 154
 155#ifdef CONFIG_DEBUG_FS
 156
 157/* XXX: cache set refcounting */
 158
 159struct dump_iterator {
 160        char                    buf[PAGE_SIZE];
 161        size_t                  bytes;
 162        struct cache_set        *c;
 163        struct keybuf           keys;
 164};
 165
 166static bool dump_pred(struct keybuf *buf, struct bkey *k)
 167{
 168        return true;
 169}
 170
 171static 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                int err = copy_to_user(buf, i->buf, bytes);
 182
 183                if (err)
 184                        return err;
 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
 207static 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
 224static int bch_dump_release(struct inode *inode, struct file *file)
 225{
 226        kfree(file->private_data);
 227        return 0;
 228}
 229
 230static 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
 237void 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->sb.set_uuid);
 243                c->debug = debugfs_create_file(name, 0400, bcache_debug, c,
 244                                               &cache_set_debug_ops);
 245        }
 246}
 247
 248#endif
 249
 250void bch_debug_exit(void)
 251{
 252        if (!IS_ERR_OR_NULL(bcache_debug))
 253                debugfs_remove_recursive(bcache_debug);
 254}
 255
 256void __init bch_debug_init(struct kobject *kobj)
 257{
 258        /*
 259         * it is unnecessary to check return value of
 260         * debugfs_create_file(), we should not care
 261         * about this.
 262         */
 263        bcache_debug = debugfs_create_dir("bcache", NULL);
 264}
 265