Linux 3.12.39

[linux/fpc-iii.git] / drivers / md / bcache / 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 "request.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;
}

int bch_btree_to_text(char *buf, size_t size, const struct btree *b)
{
        return scnprintf(buf, size, "%zu level %i/%i",
                         PTR_BUCKET_NR(b->c, &b->key, 0),
                         b->level, b->c->root ? b->c->root->level : -1);
}

#if defined(CONFIG_BCACHE_DEBUG) || defined(CONFIG_BCACHE_EDEBUG)

static bool skipped_backwards(struct btree *b, struct bkey *k)
{
        return bkey_cmp(k, (!b->level)
                        ? &START_KEY(bkey_next(k))
                        : bkey_next(k)) > 0;
}

static void dump_bset(struct btree *b, struct bset *i)
{
        struct bkey *k;
        unsigned j;
        char buf[80];

        for (k = i->start; k < end(i); k = 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 (bkey_next(k) < end(i) &&
                    skipped_backwards(b, k))
                        printk(KERN_ERR "Key skipped backwards\n");
        }
}

#endif

#ifdef CONFIG_BCACHE_DEBUG

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);
}

static void data_verify_endio(struct bio *bio, int error)
{
        struct closure *cl = bio->bi_private;
        closure_put(cl);
}

void bch_data_verify(struct search *s)
{
        char name[BDEVNAME_SIZE];
        struct cached_dev *dc = container_of(s->d, struct cached_dev, disk);
        struct closure *cl = &s->cl;
        struct bio *check;
        struct bio_vec *bv;
        int i;

        if (!s->unaligned_bvec)
                bio_for_each_segment(bv, s->orig_bio, i)
                        bv->bv_offset = 0, bv->bv_len = PAGE_SIZE;

        check = bio_clone(s->orig_bio, GFP_NOIO);
        if (!check)
                return;

        if (bio_alloc_pages(check, GFP_NOIO))
                goto out_put;

        check->bi_rw            = READ_SYNC;
        check->bi_private       = cl;
        check->bi_end_io        = data_verify_endio;

        closure_bio_submit(check, cl, &dc->disk);
        closure_sync(cl);

        bio_for_each_segment(bv, s->orig_bio, i) {
                void *p1 = kmap(bv->bv_page);
                void *p2 = kmap(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) s->orig_bio->bi_sector);

                kunmap(bv->bv_page);
                kunmap(check->bi_io_vec[i].bv_page);
        }

        __bio_for_each_segment(bv, check, i, 0)
                __free_page(bv->bv_page);
out_put:
        bio_put(check);
}

#endif

#ifdef CONFIG_BCACHE_EDEBUG

unsigned 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;
}

static void vdump_bucket_and_panic(struct btree *b, const char *fmt,
                                   va_list args)
{
        unsigned i;
        char buf[80];

        console_lock();

        for (i = 0; i <= b->nsets; i++)
                dump_bset(b, b->sets[i].data);

        vprintk(fmt, args);

        console_unlock();

        bch_btree_to_text(buf, sizeof(buf), b);
        panic("at %s\n", buf);
}

void bch_check_key_order_msg(struct btree *b, struct bset *i,
                             const char *fmt, ...)
{
        struct bkey *k;

        if (!i->keys)
                return;

        for (k = i->start; bkey_next(k) < end(i); k = bkey_next(k))
                if (skipped_backwards(b, k)) {
                        va_list args;
                        va_start(args, fmt);

                        vdump_bucket_and_panic(b, fmt, args);
                        va_end(args);
                }
}

void bch_check_keys(struct btree *b, const char *fmt, ...)
{
        va_list args;
        struct bkey *k, *p = NULL;
        struct btree_iter iter;

        if (b->level)
                return;

        for_each_key(b, k, &iter) {
                if (p && bkey_cmp(&START_KEY(p), &START_KEY(k)) > 0) {
                        printk(KERN_ERR "Keys out of order:\n");
                        goto bug;
                }

                if (bch_ptr_invalid(b, k))
                        continue;

                if (p && bkey_cmp(p, &START_KEY(k)) > 0) {
                        printk(KERN_ERR "Overlapping keys:\n");
                        goto bug;
                }
                p = k;
        }
        return;
bug:
        va_start(args, fmt);
        vdump_bucket_and_panic(b, fmt, args);
        va_end(args);
}

#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;
}