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 struct 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 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) - 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 } 107 108 void 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); 149 out_put: 150 bio_put(check); 151 } 152 153 #endif 154 155 #ifdef CONFIG_DEBUG_FS 156 157 /* XXX: cache set refcounting */ 158 159 struct dump_iterator { 160 char buf[PAGE_SIZE]; 161 size_t bytes; 162 struct cache_set *c; 163 struct keybuf keys; 164 }; 165 166 static bool dump_pred(struct keybuf *buf, struct bkey *k) 167 { 168 return true; 169 } 170 171 static 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 } 206 207 static 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 } 223 224 static int bch_dump_release(struct inode *inode, struct file *file) 225 { 226 kfree(file->private_data); 227 return 0; 228 } 229 230 static 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 }; 236 237 void 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 249 250 void bch_debug_exit(void) 251 { 252 debugfs_remove_recursive(bcache_debug); 253 } 254 255 void __init bch_debug_init(void) 256 { 257 /* 258 * it is unnecessary to check return value of 259 * debugfs_create_file(), we should not care 260 * about this. 261 */ 262 bcache_debug = debugfs_create_dir("bcache", NULL); 263 } 264