linux/drivers/md/bcache/debug.c

386 lines
7.6 KiB
C

/*
* Assorted bcache debug code
*
* Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com>
* Copyright 2012 Google, Inc.
*/
#include "bcache.h"
#include "btree.h"
#include "debug.h"
#include <linux/console.h>
#include <linux/debugfs.h>
#include <linux/module.h>
#include <linux/random.h>
#include <linux/seq_file.h>
static struct dentry *debug;
const char *bch_ptr_status(struct cache_set *c, const struct bkey *k)
{
unsigned i;
for (i = 0; i < KEY_PTRS(k); i++)
if (ptr_available(c, k, i)) {
struct cache *ca = PTR_CACHE(c, k, i);
size_t bucket = PTR_BUCKET_NR(c, k, i);
size_t r = bucket_remainder(c, PTR_OFFSET(k, i));
if (KEY_SIZE(k) + r > c->sb.bucket_size)
return "bad, length too big";
if (bucket < ca->sb.first_bucket)
return "bad, short offset";
if (bucket >= ca->sb.nbuckets)
return "bad, offset past end of device";
if (ptr_stale(c, k, i))
return "stale";
}
if (!bkey_cmp(k, &ZERO_KEY))
return "bad, null key";
if (!KEY_PTRS(k))
return "bad, no pointers";
if (!KEY_SIZE(k))
return "zeroed key";
return "";
}
int bch_bkey_to_text(char *buf, size_t size, const struct bkey *k)
{
unsigned i = 0;
char *out = buf, *end = buf + size;
#define p(...) (out += scnprintf(out, end - out, __VA_ARGS__))
p("%llu:%llu len %llu -> [", KEY_INODE(k), KEY_OFFSET(k), KEY_SIZE(k));
if (KEY_PTRS(k))
while (1) {
p("%llu:%llu gen %llu",
PTR_DEV(k, i), PTR_OFFSET(k, i), PTR_GEN(k, i));
if (++i == KEY_PTRS(k))
break;
p(", ");
}
p("]");
if (KEY_DIRTY(k))
p(" dirty");
if (KEY_CSUM(k))
p(" cs%llu %llx", KEY_CSUM(k), k->ptr[1]);
#undef p
return out - buf;
}
#ifdef CONFIG_BCACHE_DEBUG
static void dump_bset(struct btree *b, struct bset *i)
{
struct bkey *k, *next;
unsigned j;
char buf[80];
for (k = i->start; k < end(i); k = next) {
next = bkey_next(k);
bch_bkey_to_text(buf, sizeof(buf), k);
printk(KERN_ERR "block %zu key %zi/%u: %s", index(i, b),
(uint64_t *) k - i->d, i->keys, buf);
for (j = 0; j < KEY_PTRS(k); j++) {
size_t n = PTR_BUCKET_NR(b->c, k, j);
printk(" bucket %zu", n);
if (n >= b->c->sb.first_bucket && n < b->c->sb.nbuckets)
printk(" prio %i",
PTR_BUCKET(b->c, k, j)->prio);
}
printk(" %s\n", bch_ptr_status(b->c, k));
if (next < end(i) &&
bkey_cmp(k, !b->level ? &START_KEY(next) : next) > 0)
printk(KERN_ERR "Key skipped backwards\n");
}
}
static void bch_dump_bucket(struct btree *b)
{
unsigned i;
console_lock();
for (i = 0; i <= b->nsets; i++)
dump_bset(b, b->sets[i].data);
console_unlock();
}
void bch_btree_verify(struct btree *b, struct bset *new)
{
struct btree *v = b->c->verify_data;
struct closure cl;
closure_init_stack(&cl);
if (!b->c->verify)
return;
closure_wait_event(&b->io.wait, &cl,
atomic_read(&b->io.cl.remaining) == -1);
mutex_lock(&b->c->verify_lock);
bkey_copy(&v->key, &b->key);
v->written = 0;
v->level = b->level;
bch_btree_node_read(v);
closure_wait_event(&v->io.wait, &cl,
atomic_read(&b->io.cl.remaining) == -1);
if (new->keys != v->sets[0].data->keys ||
memcmp(new->start,
v->sets[0].data->start,
(void *) end(new) - (void *) new->start)) {
unsigned i, j;
console_lock();
printk(KERN_ERR "*** original memory node:\n");
for (i = 0; i <= b->nsets; i++)
dump_bset(b, b->sets[i].data);
printk(KERN_ERR "*** sorted memory node:\n");
dump_bset(b, new);
printk(KERN_ERR "*** on disk node:\n");
dump_bset(v, v->sets[0].data);
for (j = 0; j < new->keys; j++)
if (new->d[j] != v->sets[0].data->d[j])
break;
console_unlock();
panic("verify failed at %u\n", j);
}
mutex_unlock(&b->c->verify_lock);
}
void bch_data_verify(struct cached_dev *dc, struct bio *bio)
{
char name[BDEVNAME_SIZE];
struct bio *check;
struct bio_vec *bv;
int i;
check = bio_clone(bio, GFP_NOIO);
if (!check)
return;
if (bio_alloc_pages(check, GFP_NOIO))
goto out_put;
submit_bio_wait(READ_SYNC, check);
bio_for_each_segment(bv, bio, i) {
void *p1 = kmap_atomic(bv->bv_page);
void *p2 = page_address(check->bi_io_vec[i].bv_page);
if (memcmp(p1 + bv->bv_offset,
p2 + bv->bv_offset,
bv->bv_len))
printk(KERN_ERR
"bcache (%s): verify failed at sector %llu\n",
bdevname(dc->bdev, name),
(uint64_t) bio->bi_sector);
kunmap_atomic(p1);
}
bio_for_each_segment_all(bv, check, i)
__free_page(bv->bv_page);
out_put:
bio_put(check);
}
int __bch_count_data(struct btree *b)
{
unsigned ret = 0;
struct btree_iter iter;
struct bkey *k;
if (!b->level)
for_each_key(b, k, &iter)
ret += KEY_SIZE(k);
return ret;
}
void __bch_check_keys(struct btree *b, const char *fmt, ...)
{
va_list args;
struct bkey *k, *p = NULL;
struct btree_iter iter;
const char *err;
for_each_key(b, k, &iter) {
if (!b->level) {
err = "Keys out of order";
if (p && bkey_cmp(&START_KEY(p), &START_KEY(k)) > 0)
goto bug;
if (bch_ptr_invalid(b, k))
continue;
err = "Overlapping keys";
if (p && bkey_cmp(p, &START_KEY(k)) > 0)
goto bug;
} else {
if (bch_ptr_bad(b, k))
continue;
err = "Duplicate keys";
if (p && !bkey_cmp(p, k))
goto bug;
}
p = k;
}
err = "Key larger than btree node key";
if (p && bkey_cmp(p, &b->key) > 0)
goto bug;
return;
bug:
bch_dump_bucket(b);
va_start(args, fmt);
vprintk(fmt, args);
va_end(args);
panic("bcache error: %s:\n", err);
}
void bch_btree_iter_next_check(struct btree_iter *iter)
{
struct bkey *k = iter->data->k, *next = bkey_next(k);
if (next < iter->data->end &&
bkey_cmp(k, iter->b->level ? next : &START_KEY(next)) > 0) {
bch_dump_bucket(iter->b);
panic("Key skipped backwards\n");
}
}
#endif
#ifdef CONFIG_DEBUG_FS
/* XXX: cache set refcounting */
struct dump_iterator {
char buf[PAGE_SIZE];
size_t bytes;
struct cache_set *c;
struct keybuf keys;
};
static bool dump_pred(struct keybuf *buf, struct bkey *k)
{
return true;
}
static ssize_t bch_dump_read(struct file *file, char __user *buf,
size_t size, loff_t *ppos)
{
struct dump_iterator *i = file->private_data;
ssize_t ret = 0;
char kbuf[80];
while (size) {
struct keybuf_key *w;
unsigned bytes = min(i->bytes, size);
int err = copy_to_user(buf, i->buf, bytes);
if (err)
return err;
ret += bytes;
buf += bytes;
size -= bytes;
i->bytes -= bytes;
memmove(i->buf, i->buf + bytes, i->bytes);
if (i->bytes)
break;
w = bch_keybuf_next_rescan(i->c, &i->keys, &MAX_KEY, dump_pred);
if (!w)
break;
bch_bkey_to_text(kbuf, sizeof(kbuf), &w->key);
i->bytes = snprintf(i->buf, PAGE_SIZE, "%s\n", kbuf);
bch_keybuf_del(&i->keys, w);
}
return ret;
}
static int bch_dump_open(struct inode *inode, struct file *file)
{
struct cache_set *c = inode->i_private;
struct dump_iterator *i;
i = kzalloc(sizeof(struct dump_iterator), GFP_KERNEL);
if (!i)
return -ENOMEM;
file->private_data = i;
i->c = c;
bch_keybuf_init(&i->keys);
i->keys.last_scanned = KEY(0, 0, 0);
return 0;
}
static int bch_dump_release(struct inode *inode, struct file *file)
{
kfree(file->private_data);
return 0;
}
static const struct file_operations cache_set_debug_ops = {
.owner = THIS_MODULE,
.open = bch_dump_open,
.read = bch_dump_read,
.release = bch_dump_release
};
void bch_debug_init_cache_set(struct cache_set *c)
{
if (!IS_ERR_OR_NULL(debug)) {
char name[50];
snprintf(name, 50, "bcache-%pU", c->sb.set_uuid);
c->debug = debugfs_create_file(name, 0400, debug, c,
&cache_set_debug_ops);
}
}
#endif
void bch_debug_exit(void)
{
if (!IS_ERR_OR_NULL(debug))
debugfs_remove_recursive(debug);
}
int __init bch_debug_init(struct kobject *kobj)
{
int ret = 0;
debug = debugfs_create_dir("bcache", NULL);
return ret;
}