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    Subject[Bcache v14 16/16] bcache: Debug and tracing code
    Date
    Signed-off-by: Kent Overstreet <koverstreet@google.com>
    ---
    drivers/md/bcache/debug.c | 578 +++++++++++++++++++++++++++++++++++++++++++++
    drivers/md/bcache/debug.h | 54 +++++
    drivers/md/bcache/trace.c | 26 ++
    3 files changed, 658 insertions(+)
    diff --git a/drivers/md/bcache/debug.c b/drivers/md/bcache/debug.c
    new file mode 100644
    index 0000000..9c8f15a
    --- /dev/null
    +++ b/drivers/md/bcache/debug.c
    @@ -0,0 +1,578 @@
    +
    +#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;
    +
    +/* Various debug code */
    +
    +const char *bch_ptr_status(struct cache_set *c, const struct bkey *k)
    +{
    + for (unsigned 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 "";
    +}
    +
    +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)
    +{
    + for (struct bkey *k = i->start; k < end(i); k = bkey_next(k)) {
    + printk(KERN_ERR "block %zu key %zu/%i: %s", index(i, b),
    + (uint64_t *) k - i->d, i->keys, pkey(k));
    +
    + for (unsigned 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");
    + }
    +}
    +
    +static void vdump_bucket_and_panic(struct btree *b, const char *m, va_list args)
    +{
    + struct bset *i;
    +
    + console_lock();
    +
    + for_each_sorted_set(b, i)
    + dump_bset(b, i);
    +
    + vprintk(m, args);
    +
    + console_unlock();
    +
    + panic("at %s\n", pbtree(b));
    +}
    +
    +static void dump_bucket_and_panic(struct btree *b, const char *m, ...)
    +{
    + va_list args;
    + va_start(args, m);
    + vdump_bucket_and_panic(b, m, args);
    + va_end(args);
    +}
    +
    +static void __maybe_unused
    +dump_key_and_panic(struct btree *b, struct bset *i, int j)
    +{
    + long bucket = PTR_BUCKET_NR(b->c, node(i, j), 0);
    + long r = PTR_OFFSET(node(i, j), 0) & ~(~0 << b->c->bucket_bits);
    +
    + printk(KERN_ERR "level %i block %zu key %i/%i: %s "
    + "bucket %llu offset %li into bucket\n",
    + b->level, index(i, b), j, i->keys, pkey(node(i, j)),
    + (uint64_t) bucket, r);
    + dump_bucket_and_panic(b, "");
    +}
    +
    +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;
    +}
    +
    +#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)) {
    + struct bset *i;
    + unsigned j;
    +
    + console_lock();
    +
    + printk(KERN_ERR "*** original memory node:\n");
    + for_each_sorted_set(b, i)
    + dump_bset(b, i);
    +
    + 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);
    + 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 bkey *k;
    +
    + if (!b->level)
    + for_each_key(b, k)
    + ret += KEY_SIZE(k);
    + return ret;
    +}
    +
    +void bch_check_key_order_msg(struct btree *b, struct bset *i, const char *m, ...)
    +{
    + if (!i->keys)
    + return;
    +
    + for (struct bkey *k = i->start; bkey_next(k) < end(i); k = bkey_next(k))
    + if (skipped_backwards(b, k)) {
    + va_list args;
    + va_start(args, m);
    +
    + vdump_bucket_and_panic(b, m, args);
    + va_end(args);
    + }
    +}
    +
    +void bch_check_keys(struct btree *b, const char *m, ...)
    +{
    + va_list args;
    + struct bkey *k, *p;
    + struct btree_iter iter;
    +
    + if (b->level)
    + return;
    +
    + bch_btree_iter_init(b, &iter, NULL);
    +
    + do
    + p = bch_btree_iter_next(&iter);
    + while (p && bch_ptr_invalid(b, p));
    +
    + while ((k = bch_btree_iter_next(&iter))) {
    + if (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 (bkey_cmp(p, &START_KEY(k)) > 0) {
    + printk(KERN_ERR "Overlapping keys:\n");
    + goto bug;
    + }
    + p = k;
    + }
    + return;
    +bug:
    + va_start(args, m);
    + vdump_bucket_and_panic(b, m, args);
    + va_end(args);
    +}
    +
    +#endif
    +
    +#ifdef CONFIG_DEBUG_FS
    +
    +static int bch_btree_dump(struct btree *b, struct btree_op *op, struct seq_file *f,
    + const char *tabs, uint64_t *prev, uint64_t *sectors)
    +{
    + struct bkey *k;
    + char buf[30];
    + uint64_t last, biggest = 0;
    +
    + for_each_key(b, k) {
    + int j = (uint64_t *) k - _t->data->d;
    + if (!j)
    + last = *prev;
    +
    + if (last > KEY_OFFSET(k))
    + seq_printf(f, "Key skipped backwards\n");
    +
    + if (!b->level && j &&
    + last != KEY_START(k))
    + seq_printf(f, "<hole>\n");
    + else if (b->level && !bch_ptr_bad(b, k))
    + btree(dump, k, b, op, f, tabs - 1, &last, sectors);
    +
    + seq_printf(f, "%s%zi %4i: %s %s\n",
    + tabs, _t - b->sets, j, pkey(k), buf);
    +
    + if (!b->level && !buf[0])
    + *sectors += KEY_SIZE(k);
    +
    + last = KEY_OFFSET(k);
    + biggest = max(biggest, last);
    + }
    + *prev = biggest;
    +
    + return 0;
    +}
    +
    +static int debug_seq_show(struct seq_file *f, void *data)
    +{
    + static const char *tabs = "\t\t\t\t\t";
    + uint64_t last = 0, sectors = 0;
    + struct cache_set *c = f->private;
    +
    + struct btree_op op;
    + bch_btree_op_init_stack(&op);
    +
    + btree_root(dump, c, &op, f, &tabs[4], &last, &sectors);
    +
    + seq_printf(f, "%s\n" "%llu Mb found\n",
    + pkey(&c->root->key), sectors / 2048);
    +
    + closure_sync(&op.cl);
    + return 0;
    +}
    +
    +static int debug_seq_open(struct inode *inode, struct file *file)
    +{
    + return single_open(file, debug_seq_show, inode->i_private);
    +}
    +
    +static const struct file_operations cache_set_debug_ops = {
    + .owner = THIS_MODULE,
    + .open = debug_seq_open,
    + .read = seq_read,
    + .release = single_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)
    + {
    + for (struct bset *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;
    +
    + 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 (int i = 0; i < 3; i++) {
    + BUG_ON(list_empty(&c->btree_cache));
    + all[i] = list_first_entry(&c->btree_cache, struct btree, list);
    + list_del_init(&all[i]->list);
    +
    + all[i]->key = KEY(0, 0, c->sb.bucket_size);
    + bkey_copy_key(&all[i]->key, &MAX_KEY);
    + }
    +
    + b = all[0];
    + fill = all[1];
    + orig = all[2];
    +
    + while (1) {
    + for (int i = 0; i < 3; i++)
    + all[i]->written = all[i]->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;
    +
    + for (struct bkey *k = i->start,
    + *j = fill->sets[0].data->start;
    + k < end(i);
    + k = bkey_next(k), j = bkey_next(j))
    + if (bkey_cmp(k, j) ||
    + KEY_SIZE(k) != KEY_SIZE(j))
    + printk(KERN_ERR "key %zi differs: %s "
    + "!= %s\n", (uint64_t *) k - i->d,
    + pkey(k), pkey(j));
    +
    + for (int i = 0; i < 3; i++) {
    + printk(KERN_ERR "**** Set %i ****\n", i);
    + dump(all[i]);
    + }
    + panic("\n");
    + }
    +
    + printk(KERN_DEBUG "bcache: fuzz complete: %i keys\n",
    + b->sets[0].data->keys);
    + }
    +}
    +
    +kobj_attribute_write(fuzz, btree_fuzz);
    +#endif
    +
    +#ifdef CONFIG_BCACHE_LATENCY_DEBUG
    +static ssize_t show(struct kobject *k, struct kobj_attribute *attr, char *buf)
    +{
    + return snprintf(buf, PAGE_SIZE, "%i\n", latency_warn_ms);
    +}
    +
    +static ssize_t store(struct kobject *k, struct kobj_attribute *attr,
    + const char *buffer, size_t size)
    +{
    + return strtoul_safe(buffer, latency_warn_ms) ?: (ssize_t) size;
    +}
    +
    +kobj_attribute_rw(latency_warn_ms, show, store);
    +#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
    +
    +#ifdef CONFIG_BCACHE_LATENCY_DEBUG
    + ret = sysfs_create_file(kobj, &ksysfs_latency_warn_ms.attr);
    + if (ret)
    + return ret;
    +#endif
    +
    + debug = debugfs_create_dir("bcache", NULL);
    + return ret;
    +}
    diff --git a/drivers/md/bcache/debug.h b/drivers/md/bcache/debug.h
    new file mode 100644
    index 0000000..f9378a2
    --- /dev/null
    +++ b/drivers/md/bcache/debug.h
    @@ -0,0 +1,54 @@
    +#ifndef _BCACHE_DEBUG_H
    +#define _BCACHE_DEBUG_H
    +
    +/* Btree/bkey debug printing */
    +
    +#define KEYHACK_SIZE 80
    +struct keyprint_hack {
    + char s[KEYHACK_SIZE];
    +};
    +
    +struct keyprint_hack bch_pkey(const struct bkey *k);
    +struct keyprint_hack bch_pbtree(const struct btree *b);
    +#define pkey(k) (&bch_pkey(k).s[0])
    +#define pbtree(b) (&bch_pbtree(b).s[0])
    +
    +#ifdef CONFIG_BCACHE_EDEBUG
    +
    +unsigned bch_count_data(struct btree *);
    +void bch_check_key_order_msg(struct btree *, struct bset *, const char *, ...);
    +void bch_check_keys(struct btree *, const char *, ...);
    +
    +#define bch_check_key_order(b, i) \
    + bch_check_key_order_msg(b, i, "keys out of order")
    +#define EBUG_ON(cond) BUG_ON(cond)
    +
    +#else /* EDEBUG */
    +
    +#define bch_count_data(b) 0
    +#define bch_check_key_order(b, i) do {} while (0)
    +#define bch_check_key_order_msg(b, i, ...) do {} while (0)
    +#define bch_check_keys(b, ...) do {} while (0)
    +#define EBUG_ON(cond) do {} while (0)
    +
    +#endif
    +
    +#ifdef CONFIG_BCACHE_DEBUG
    +
    +void bch_btree_verify(struct btree *, struct bset *);
    +void bch_data_verify(struct search *);
    +
    +#else /* DEBUG */
    +
    +static inline void bch_btree_verify(struct btree *b, struct bset *i) {}
    +static inline void bch_data_verify(struct search *s) {};
    +
    +#endif
    +
    +#ifdef CONFIG_DEBUG_FS
    +void bch_debug_init_cache_set(struct cache_set *);
    +#else
    +static inline void bch_debug_init_cache_set(struct cache_set *c) {}
    +#endif
    +
    +#endif
    diff --git a/drivers/md/bcache/trace.c b/drivers/md/bcache/trace.c
    new file mode 100644
    index 0000000..983f9bb
    --- /dev/null
    +++ b/drivers/md/bcache/trace.c
    @@ -0,0 +1,26 @@
    +#include "bcache.h"
    +#include "btree.h"
    +#include "request.h"
    +
    +#include <linux/module.h>
    +
    +#define CREATE_TRACE_POINTS
    +#include <trace/events/bcache.h>
    +
    +EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_request_start);
    +EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_request_end);
    +EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_passthrough);
    +EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_cache_hit);
    +EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_cache_miss);
    +EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_read_retry);
    +EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_writethrough);
    +EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_writeback);
    +EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_write_skip);
    +EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_btree_read);
    +EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_btree_write);
    +EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_write_dirty);
    +EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_read_dirty);
    +EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_journal_write);
    +EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_cache_insert);
    +EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_gc_start);
    +EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_gc_end);
    --
    1.7.9.3.327.g2980b


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      Last update: 2012-06-13 00:04    [W:0.390 / U:0.100 seconds]
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