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Commit 280481d0 authored by Kent Overstreet's avatar Kent Overstreet
Browse files

bcache: Debug code improvements 



Couple changes:
 * Consolidate bch_check_keys() and bch_check_key_order(), and move the
   checks that only check_key_order() could do to bch_btree_iter_next().

 * Get rid of CONFIG_BCACHE_EDEBUG - now, all that code is compiled in
   when CONFIG_BCACHE_DEBUG is enabled, and there's now a sysfs file to
   flip on the EDEBUG checks at runtime.

 * Dropped an old not terribly useful check in rw_unlock(), and
   refactored/improved a some of the other debug code.

Signed-off-by: default avatarKent Overstreet <kmo@daterainc.com>
parent e58ff155

drivers/md/bcache/Kconfig

+2 −9
Original line number Diff line number Diff line
@@ -13,15 +13,8 @@ config BCACHE_DEBUG 
	---help---

	Don't select this option unless you're a developer



	Enables extra debugging tools (primarily a fuzz tester)



config BCACHE_EDEBUG

	bool "Extended runtime checks"

	depends on BCACHE

	---help---

	Don't select this option unless you're a developer



	Enables extra runtime checks which significantly affect performance

	Enables extra debugging tools, allows expensive runtime checks to be

	turned on.



config BCACHE_CLOSURES_DEBUG

	bool "Debug closures"

drivers/md/bcache/alloc.c

+2 −3
Original line number Diff line number Diff line
@@ -398,8 +398,7 @@ long bch_bucket_alloc(struct cache *ca, unsigned watermark, bool wait) 
out:

	wake_up_process(ca->alloc_thread);



#ifdef CONFIG_BCACHE_EDEBUG

	{

	if (expensive_debug_checks(ca->set)) {

		size_t iter;

		long i;
@@ -413,7 +412,7 @@ long bch_bucket_alloc(struct cache *ca, unsigned watermark, bool wait) 
		fifo_for_each(i, &ca->unused, iter)

			BUG_ON(i == r);

	}

#endif



	b = ca->buckets + r;



	BUG_ON(atomic_read(&b->pin) != 1);

drivers/md/bcache/bcache.h

+1 −9
Original line number Diff line number Diff line
@@ -690,6 +690,7 @@ struct cache_set { 
	unsigned short		journal_delay_ms;

	unsigned		verify:1;

	unsigned		key_merging_disabled:1;

	unsigned		expensive_debug_checks:1;

	unsigned		gc_always_rewrite:1;

	unsigned		shrinker_disabled:1;

	unsigned		copy_gc_enabled:1;
@@ -698,15 +699,6 @@ struct cache_set { 
	struct hlist_head	bucket_hash[1 << BUCKET_HASH_BITS];

};



static inline bool key_merging_disabled(struct cache_set *c)

{

#ifdef CONFIG_BCACHE_DEBUG

	return c->key_merging_disabled;

#else

	return 0;

#endif

}



struct bbio {

	unsigned		submit_time_us;

	union {

drivers/md/bcache/bset.c

+60 −52
Original line number Diff line number Diff line
@@ -106,6 +106,43 @@ bool __bch_ptr_invalid(struct cache_set *c, int level, const struct bkey *k) 
	return true;

}



static bool ptr_bad_expensive_checks(struct btree *b, const struct bkey *k,

				     unsigned ptr)

{

	struct bucket *g = PTR_BUCKET(b->c, k, ptr);

	char buf[80];



	if (mutex_trylock(&b->c->bucket_lock)) {

		if (b->level) {

			if (KEY_DIRTY(k) ||

			    g->prio != BTREE_PRIO ||

			    (b->c->gc_mark_valid &&

			     GC_MARK(g) != GC_MARK_METADATA))

				goto err;



		} else {

			if (g->prio == BTREE_PRIO)

				goto err;



			if (KEY_DIRTY(k) &&

			    b->c->gc_mark_valid &&

			    GC_MARK(g) != GC_MARK_DIRTY)

				goto err;

		}

		mutex_unlock(&b->c->bucket_lock);

	}



	return false;

err:

	mutex_unlock(&b->c->bucket_lock);

	bch_bkey_to_text(buf, sizeof(buf), k);

	btree_bug(b,

"inconsistent pointer %s: bucket %zu pin %i prio %i gen %i last_gc %i mark %llu gc_gen %i",

		  buf, PTR_BUCKET_NR(b->c, k, ptr), atomic_read(&g->pin),

		  g->prio, g->gen, g->last_gc, GC_MARK(g), g->gc_gen);

	return true;

}



bool bch_ptr_bad(struct btree *b, const struct bkey *k)

{

	struct bucket *g;
@@ -133,46 +170,12 @@ bool bch_ptr_bad(struct btree *b, const struct bkey *k) 
		if (stale)

			return true;



#ifdef CONFIG_BCACHE_EDEBUG

		if (!mutex_trylock(&b->c->bucket_lock))

			continue;



		if (b->level) {

			if (KEY_DIRTY(k) ||

			    g->prio != BTREE_PRIO ||

			    (b->c->gc_mark_valid &&

			     GC_MARK(g) != GC_MARK_METADATA))

				goto bug;



		} else {

			if (g->prio == BTREE_PRIO)

				goto bug;



			if (KEY_DIRTY(k) &&

			    b->c->gc_mark_valid &&

			    GC_MARK(g) != GC_MARK_DIRTY)

				goto bug;

		}

		mutex_unlock(&b->c->bucket_lock);

#endif

		if (expensive_debug_checks(b->c) &&

		    ptr_bad_expensive_checks(b, k, i))

			return true;

	}



	return false;

#ifdef CONFIG_BCACHE_EDEBUG

bug:

	mutex_unlock(&b->c->bucket_lock);



	{

		char buf[80];



		bch_bkey_to_text(buf, sizeof(buf), k);

		btree_bug(b,

"inconsistent pointer %s: bucket %zu pin %i prio %i gen %i last_gc %i mark %llu gc_gen %i",

			  buf, PTR_BUCKET_NR(b->c, k, i), atomic_read(&g->pin),

			  g->prio, g->gen, g->last_gc, GC_MARK(g), g->gc_gen);

	}

	return true;

#endif

}



/* Key/pointer manipulation */
@@ -821,7 +824,7 @@ struct bkey *__bch_bset_search(struct btree *b, struct bset_tree *t, 
	} else

		i = bset_search_write_set(b, t, search);



#ifdef CONFIG_BCACHE_EDEBUG

	if (expensive_debug_checks(b->c)) {

		BUG_ON(bset_written(b, t) &&

		       i.l != t->data->start &&

		       bkey_cmp(tree_to_prev_bkey(t,
@@ -830,7 +833,7 @@ struct bkey *__bch_bset_search(struct btree *b, struct bset_tree *t, 


		BUG_ON(i.r != end(t->data) &&

		       bkey_cmp(i.r, search) <= 0);

#endif

	}



	while (likely(i.l != i.r) &&

	       bkey_cmp(i.l, search) <= 0)
@@ -877,6 +880,10 @@ struct bkey *__bch_btree_iter_init(struct btree *b, struct btree_iter *iter, 
	iter->size = ARRAY_SIZE(iter->data);

	iter->used = 0;



#ifdef CONFIG_BCACHE_DEBUG

	iter->b = b;

#endif



	for (; start <= &b->sets[b->nsets]; start++) {

		ret = bch_bset_search(b, start, search);

		bch_btree_iter_push(iter, ret, end(start->data));
@@ -891,6 +898,8 @@ struct bkey *bch_btree_iter_next(struct btree_iter *iter) 
	struct bkey *ret = NULL;



	if (!btree_iter_end(iter)) {

		bch_btree_iter_next_check(iter);



		ret = iter->data->k;

		iter->data->k = bkey_next(iter->data->k);
@@ -1002,7 +1011,6 @@ static void btree_mergesort(struct btree *b, struct bset *out, 
	out->keys = last ? (uint64_t *) bkey_next(last) - out->d : 0;



	pr_debug("sorted %i keys", out->keys);

	bch_check_key_order(b, out);

}



static void __btree_sort(struct btree *b, struct btree_iter *iter,
@@ -1063,15 +1071,15 @@ static void __btree_sort(struct btree *b, struct btree_iter *iter, 


void bch_btree_sort_partial(struct btree *b, unsigned start)

{

	size_t oldsize = 0, order = b->page_order, keys = 0;

	size_t order = b->page_order, keys = 0;

	struct btree_iter iter;

	int oldsize = bch_count_data(b);



	__bch_btree_iter_init(b, &iter, NULL, &b->sets[start]);



	BUG_ON(b->sets[b->nsets].data == write_block(b) &&

	       (b->sets[b->nsets].size || b->nsets));



	if (b->written)

		oldsize = bch_count_data(b);



	if (start) {

		unsigned i;
@@ -1087,7 +1095,7 @@ void bch_btree_sort_partial(struct btree *b, unsigned start) 


	__btree_sort(b, &iter, start, order, false);



	EBUG_ON(b->written && bch_count_data(b) != oldsize);

	EBUG_ON(b->written && oldsize >= 0 && bch_count_data(b) != oldsize);

}



void bch_btree_sort_and_fix_extents(struct btree *b, struct btree_iter *iter)

drivers/md/bcache/bset.h

+3 −0
Original line number Diff line number Diff line
@@ -148,6 +148,9 @@ 


struct btree_iter {

	size_t size, used;

#ifdef CONFIG_BCACHE_DEBUG

	struct btree *b;

#endif

	struct btree_iter_set {

		struct bkey *k, *end;

	} data[MAX_BSETS];