Commit 4fe6a816 authored by Kent Overstreet's avatar Kent Overstreet
Browse files

bcache: Add a real GC_MARK_RECLAIMABLE 



This means the garbage collection code can better check for data and metadata
pointers to the same buckets.

Signed-off-by: default avatarKent Overstreet <kmo@daterainc.com>
parent c13f3af9

drivers/md/bcache/alloc.c

+3 −2
Original line number Diff line number Diff line
@@ -155,7 +155,8 @@ bool bch_bucket_add_unused(struct cache *ca, struct bucket *b) 


static bool can_invalidate_bucket(struct cache *ca, struct bucket *b)

{

	return GC_MARK(b) == GC_MARK_RECLAIMABLE &&

	return (!GC_MARK(b) ||

		GC_MARK(b) == GC_MARK_RECLAIMABLE) &&

		!atomic_read(&b->pin) &&

		can_inc_bucket_gen(b);

}
@@ -475,7 +476,7 @@ void bch_bucket_free(struct cache_set *c, struct bkey *k) 
	for (i = 0; i < KEY_PTRS(k); i++) {

		struct bucket *b = PTR_BUCKET(c, k, i);



		SET_GC_MARK(b, GC_MARK_RECLAIMABLE);

		SET_GC_MARK(b, 0);

		SET_GC_SECTORS_USED(b, 0);

		bch_bucket_add_unused(PTR_CACHE(c, k, i), b);

	}

drivers/md/bcache/bcache.h

+3 −3
Original line number Diff line number Diff line
@@ -207,9 +207,9 @@ struct bucket { 
 */



BITMASK(GC_MARK,	 struct bucket, gc_mark, 0, 2);

#define GC_MARK_RECLAIMABLE	0

#define GC_MARK_DIRTY		1

#define GC_MARK_METADATA	2

#define GC_MARK_RECLAIMABLE	1

#define GC_MARK_DIRTY		2

#define GC_MARK_METADATA	3

#define GC_SECTORS_USED_SIZE	13

#define MAX_GC_SECTORS_USED	(~(~0ULL << GC_SECTORS_USED_SIZE))

BITMASK(GC_SECTORS_USED, struct bucket, gc_mark, 2, GC_SECTORS_USED_SIZE);

drivers/md/bcache/btree.c

+12 −6
Original line number Diff line number Diff line
@@ -1160,6 +1160,8 @@ static uint8_t __bch_btree_mark_key(struct cache_set *c, int level, 
			SET_GC_MARK(g, GC_MARK_METADATA);

		else if (KEY_DIRTY(k))

			SET_GC_MARK(g, GC_MARK_DIRTY);

		else if (!GC_MARK(g))

			SET_GC_MARK(g, GC_MARK_RECLAIMABLE);



		/* guard against overflow */

		SET_GC_SECTORS_USED(g, min_t(unsigned,
@@ -1559,7 +1561,7 @@ static void btree_gc_start(struct cache_set *c) 
		for_each_bucket(b, ca) {

			b->gc_gen = b->gen;

			if (!atomic_read(&b->pin)) {

				SET_GC_MARK(b, GC_MARK_RECLAIMABLE);

				SET_GC_MARK(b, 0);

				SET_GC_SECTORS_USED(b, 0);

			}

		}
@@ -1622,14 +1624,18 @@ size_t bch_btree_gc_finish(struct cache_set *c) 
			b->last_gc	= b->gc_gen;

			c->need_gc	= max(c->need_gc, bucket_gc_gen(b));



			if (!atomic_read(&b->pin) &&

			    GC_MARK(b) == GC_MARK_RECLAIMABLE) {

			if (atomic_read(&b->pin))

				continue;



			BUG_ON(!GC_MARK(b) && GC_SECTORS_USED(b));



			if (!GC_MARK(b) || GC_MARK(b) == GC_MARK_RECLAIMABLE)

				available++;

				if (!GC_SECTORS_USED(b))



			if (!GC_MARK(b))

				bch_bucket_add_unused(ca, b);

		}

	}

	}



	mutex_unlock(&c->bucket_lock);

	return available;

drivers/md/bcache/extents.c

+3 −3
Original line number Diff line number Diff line
@@ -499,9 +499,9 @@ static bool bch_extent_bad_expensive(struct btree *b, const struct bkey *k, 


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

		if (b->c->gc_mark_valid &&

		    ((GC_MARK(g) != GC_MARK_DIRTY &&

		      KEY_DIRTY(k)) ||

		     GC_MARK(g) == GC_MARK_METADATA))

		    (!GC_MARK(g) ||

		     GC_MARK(g) == GC_MARK_METADATA ||

		     (GC_MARK(g) != GC_MARK_DIRTY && KEY_DIRTY(k))))

			goto err;



		if (g->prio == BTREE_PRIO)