1 files changed, 563 insertions, 0 deletions

diff --git a/drivers/md/bcache/debug.c b/drivers/md/bcache/debug.c
new file mode 100644
index 000000000000..4b37ef2b80e5
--- /dev/null
+++ b/drivers/md/bcache/debug.c
@@ -0,0 +1,563 @@
+/*
+ * 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 "";
+}
+
+struct keyprint_hack bch_pkey(const struct bkey *k)
+{
+        unsigned i = 0;
+        struct keyprint_hack r;
+        char *out = r.s, *end = r.s + KEYHACK_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 r;
+}
+
+struct keyprint_hack bch_pbtree(const struct btree *b)
+{
+        struct keyprint_hack r;
+
+        snprintf(r.s, 40, "%li level %i/%i", PTR_BUCKET_NR(b->c, &b->key, 0),
+                 b->level, b->c->root ? b->c->root->level : -1);
+        return r;
+}
+
+#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;
+
+        for (k = i->start; k < end(i); k = bkey_next(k)) {
+                printk(KERN_ERR "block %zu key %zi/%u: %s", index(i, b),
+                       (uint64_t *) k - i->d, i->keys, pkey(k));
+
+                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_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;
+
+        console_lock();
+
+        for (i = 0; i <= b->nsets; i++)
+                dump_bset(b, b->sets[i].data);
+
+        vprintk(fmt, args);
+
+        console_unlock();
+
+        panic("at %s\n", pbtree(b));
+}
+
+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;
+
+        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);
+                if (!w)
+                        break;
+
+                i->bytes = snprintf(i->buf, PAGE_SIZE, "%s\n", pkey(&w->key));
+                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, dump_pred);
+        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
+
+#ifdef CONFIG_BCACHE_DEBUG
+static ssize_t btree_fuzz(struct kobject *k, struct kobj_attribute *a,
+                          const char *buffer, size_t size)
+{
+        void dump(struct btree *b)
+        {
+                struct bset *i;
+
+                for (i = b->sets[0].data;
+                     index(i, b) < btree_blocks(b) &&
+                     i->seq == b->sets[0].data->seq;
+                     i = ((void *) i) + set_blocks(i, b->c) * block_bytes(b->c))
+                        dump_bset(b, i);
+        }
+
+        struct cache_sb *sb;
+        struct cache_set *c;
+        struct btree *all[3], *b, *fill, *orig;
+        int j;
+
+        struct btree_op op;
+        bch_btree_op_init_stack(&op);
+
+        sb = kzalloc(sizeof(struct cache_sb), GFP_KERNEL);
+        if (!sb)
+                return -ENOMEM;
+
+        sb->bucket_size = 128;
+        sb->block_size = 4;
+
+        c = bch_cache_set_alloc(sb);
+        if (!c)
+                return -ENOMEM;
+
+        for (j = 0; j < 3; j++) {
+                BUG_ON(list_empty(&c->btree_cache));
+                all[j] = list_first_entry(&c->btree_cache, struct btree, list);
+                list_del_init(&all[j]->list);
+
+                all[j]->key = KEY(0, 0, c->sb.bucket_size);
+                bkey_copy_key(&all[j]->key, &MAX_KEY);
+        }
+
+        b = all[0];
+        fill = all[1];
+        orig = all[2];
+
+        while (1) {
+                for (j = 0; j < 3; j++)
+                        all[j]->written = all[j]->nsets = 0;
+
+                bch_bset_init_next(b);
+
+                while (1) {
+                        struct bset *i = write_block(b);
+                        struct bkey *k = op.keys.top;
+                        unsigned rand;
+
+                        bkey_init(k);
+                        rand = get_random_int();
+
+                        op.type = rand & 1
+                                ? BTREE_INSERT
+                                : BTREE_REPLACE;
+                        rand >>= 1;
+
+                        SET_KEY_SIZE(k, bucket_remainder(c, rand));
+                        rand >>= c->bucket_bits;
+                        rand &= 1024 * 512 - 1;
+                        rand += c->sb.bucket_size;
+                        SET_KEY_OFFSET(k, rand);
+#if 0
+                        SET_KEY_PTRS(k, 1);
+#endif
+                        bch_keylist_push(&op.keys);
+                        bch_btree_insert_keys(b, &op);
+
+                        if (should_split(b) ||
+                            set_blocks(i, b->c) !=
+                            __set_blocks(i, i->keys + 15, b->c)) {
+                                i->csum = csum_set(i);
+
+                                memcpy(write_block(fill),
+                                       i, set_bytes(i));
+
+                                b->written += set_blocks(i, b->c);
+                                fill->written = b->written;
+                                if (b->written == btree_blocks(b))
+                                        break;
+
+                                bch_btree_sort_lazy(b);
+                                bch_bset_init_next(b);
+                        }
+                }
+
+                memcpy(orig->sets[0].data,
+                       fill->sets[0].data,
+                       btree_bytes(c));
+
+                bch_btree_sort(b);
+                fill->written = 0;
+                bch_btree_read_done(&fill->io.cl);
+
+                if (b->sets[0].data->keys != fill->sets[0].data->keys ||
+                    memcmp(b->sets[0].data->start,
+                           fill->sets[0].data->start,
+                           b->sets[0].data->keys * sizeof(uint64_t))) {
+                        struct bset *i = b->sets[0].data;
+                        struct bkey *k, *l;
+
+                        for (k = i->start,
+                             l = fill->sets[0].data->start;
+                             k < end(i);
+                             k = bkey_next(k), l = bkey_next(l))
+                                if (bkey_cmp(k, l) ||
+                                    KEY_SIZE(k) != KEY_SIZE(l))
+                                        pr_err("key %zi differs: %s "
+                                               "!= %s", (uint64_t *) k - i->d,
+                                               pkey(k), pkey(l));
+
+                        for (j = 0; j < 3; j++) {
+                                pr_err("**** Set %i ****", j);
+                                dump(all[j]);
+                        }
+                        panic("\n");
+                }
+
+                pr_info("fuzz complete: %i keys", b->sets[0].data->keys);
+        }
+}
+
+kobj_attribute_write(fuzz, btree_fuzz);
+#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;
+#ifdef CONFIG_BCACHE_DEBUG
+        ret = sysfs_create_file(kobj, &ksysfs_fuzz.attr);
+        if (ret)
+                return ret;
+#endif
+
+        debug = debugfs_create_dir("bcache", NULL);
+        return ret;
+}