https://github.com/torvalds/linux
Tip revision: 0f33be009b89d2268e94194dc4fd01a7851b6d51 authored by Linus Torvalds on 21 September 2014, 22:43:02 UTC
Linux 3.17-rc6
Linux 3.17-rc6
Tip revision: 0f33be0
debug.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 "extents.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;
#ifdef CONFIG_BCACHE_DEBUG
#define for_each_written_bset(b, start, i) \
for (i = (start); \
(void *) i < (void *) (start) + (KEY_SIZE(&b->key) << 9) &&\
i->seq == (start)->seq; \
i = (void *) i + set_blocks(i, block_bytes(b->c)) * \
block_bytes(b->c))
void bch_btree_verify(struct btree *b)
{
struct btree *v = b->c->verify_data;
struct bset *ondisk, *sorted, *inmemory;
struct bio *bio;
if (!b->c->verify || !b->c->verify_ondisk)
return;
down(&b->io_mutex);
mutex_lock(&b->c->verify_lock);
ondisk = b->c->verify_ondisk;
sorted = b->c->verify_data->keys.set->data;
inmemory = b->keys.set->data;
bkey_copy(&v->key, &b->key);
v->written = 0;
v->level = b->level;
v->keys.ops = b->keys.ops;
bio = bch_bbio_alloc(b->c);
bio->bi_bdev = PTR_CACHE(b->c, &b->key, 0)->bdev;
bio->bi_iter.bi_sector = PTR_OFFSET(&b->key, 0);
bio->bi_iter.bi_size = KEY_SIZE(&v->key) << 9;
bch_bio_map(bio, sorted);
submit_bio_wait(REQ_META|READ_SYNC, bio);
bch_bbio_free(bio, b->c);
memcpy(ondisk, sorted, KEY_SIZE(&v->key) << 9);
bch_btree_node_read_done(v);
sorted = v->keys.set->data;
if (inmemory->keys != sorted->keys ||
memcmp(inmemory->start,
sorted->start,
(void *) bset_bkey_last(inmemory) - (void *) inmemory->start)) {
struct bset *i;
unsigned j;
console_lock();
printk(KERN_ERR "*** in memory:\n");
bch_dump_bset(&b->keys, inmemory, 0);
printk(KERN_ERR "*** read back in:\n");
bch_dump_bset(&v->keys, sorted, 0);
for_each_written_bset(b, ondisk, i) {
unsigned block = ((void *) i - (void *) ondisk) /
block_bytes(b->c);
printk(KERN_ERR "*** on disk block %u:\n", block);
bch_dump_bset(&b->keys, i, block);
}
printk(KERN_ERR "*** block %zu not written\n",
((void *) i - (void *) ondisk) / block_bytes(b->c));
for (j = 0; j < inmemory->keys; j++)
if (inmemory->d[j] != sorted->d[j])
break;
printk(KERN_ERR "b->written %u\n", b->written);
console_unlock();
panic("verify failed at %u\n", j);
}
mutex_unlock(&b->c->verify_lock);
up(&b->io_mutex);
}
void bch_data_verify(struct cached_dev *dc, struct bio *bio)
{
char name[BDEVNAME_SIZE];
struct bio *check;
struct bio_vec bv, *bv2;
struct bvec_iter iter;
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, iter) {
void *p1 = kmap_atomic(bv.bv_page);
void *p2 = page_address(check->bi_io_vec[iter.bi_idx].bv_page);
cache_set_err_on(memcmp(p1 + bv.bv_offset,
p2 + bv.bv_offset,
bv.bv_len),
dc->disk.c,
"verify failed at dev %s sector %llu",
bdevname(dc->bdev, name),
(uint64_t) bio->bi_iter.bi_sector);
kunmap_atomic(p1);
}
bio_for_each_segment_all(bv2, check, i)
__free_page(bv2->bv_page);
out_put:
bio_put(check);
}
#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_extent_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;
}