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