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 } 255