dm transaction manager: add support for prefetching blocks of metadata (4646015d) · Commits · e / devices / android_kernel_oneplus_sm8150

drivers/md/persistent-data/dm-transaction-manager.c

+75 −2

Original line number	Original line	Diff line number	Diff line
	@@ -10,6 +10,8 @@
	#include "dm-persistent-data-internal.h"		#include "dm-persistent-data-internal.h"

	#include <linux/export.h>		#include <linux/export.h>
			#include <linux/mutex.h>
			#include <linux/hash.h>
	#include <linux/slab.h>		#include <linux/slab.h>
	#include <linux/device-mapper.h>		#include <linux/device-mapper.h>

	@@ -17,6 +19,61 @@

	/----------------------------------------------------------------/		/----------------------------------------------------------------/

			#define PREFETCH_SIZE 128
			#define PREFETCH_BITS 7
			#define PREFETCH_SENTINEL ((dm_block_t) -1ULL)

			struct prefetch_set {
			struct mutex lock;
			dm_block_t blocks[PREFETCH_SIZE];
			};

			static unsigned prefetch_hash(dm_block_t b)
			{
			return hash_64(b, PREFETCH_BITS);
			}

			static void prefetch_wipe(struct prefetch_set *p)
			{
			unsigned i;
			for (i = 0; i < PREFETCH_SIZE; i++)
			p->blocks[i] = PREFETCH_SENTINEL;
			}

			static void prefetch_init(struct prefetch_set *p)
			{
			mutex_init(&p->lock);
			prefetch_wipe(p);
			}

			static void prefetch_add(struct prefetch_set *p, dm_block_t b)
			{
			unsigned h = prefetch_hash(b);

			mutex_lock(&p->lock);
			if (p->blocks[h] == PREFETCH_SENTINEL)
			p->blocks[h] = b;

			mutex_unlock(&p->lock);
			}

			static void prefetch_issue(struct prefetch_set p, struct dm_block_manager bm)
			{
			unsigned i;

			mutex_lock(&p->lock);

			for (i = 0; i < PREFETCH_SIZE; i++)
			if (p->blocks[i] != PREFETCH_SENTINEL) {
			dm_bm_prefetch(bm, p->blocks[i]);
			p->blocks[i] = PREFETCH_SENTINEL;
			}

			mutex_unlock(&p->lock);
			}

			/----------------------------------------------------------------/

	struct shadow_info {		struct shadow_info {
	struct hlist_node hlist;		struct hlist_node hlist;
	dm_block_t where;		dm_block_t where;
	@@ -37,6 +94,8 @@ struct dm_transaction_manager {

	spinlock_t lock;		spinlock_t lock;
	struct hlist_head buckets[DM_HASH_SIZE];		struct hlist_head buckets[DM_HASH_SIZE];

			struct prefetch_set prefetches;
	};		};

	/----------------------------------------------------------------/		/----------------------------------------------------------------/
	@@ -117,6 +176,8 @@ static struct dm_transaction_manager dm_tm_create(struct dm_block_manager bm,
	for (i = 0; i < DM_HASH_SIZE; i++)		for (i = 0; i < DM_HASH_SIZE; i++)
	INIT_HLIST_HEAD(tm->buckets + i);		INIT_HLIST_HEAD(tm->buckets + i);

			prefetch_init(&tm->prefetches);

	return tm;		return tm;
	}		}

	@@ -268,8 +329,14 @@ int dm_tm_read_lock(struct dm_transaction_manager *tm, dm_block_t b,
	struct dm_block_validator *v,		struct dm_block_validator *v,
	struct dm_block **blk)		struct dm_block **blk)
	{		{
	if (tm->is_clone)		if (tm->is_clone) {
	return dm_bm_read_try_lock(tm->real->bm, b, v, blk);		int r = dm_bm_read_try_lock(tm->real->bm, b, v, blk);

			if (r == -EWOULDBLOCK)
			prefetch_add(&tm->real->prefetches, b);

			return r;
			}

	return dm_bm_read_lock(tm->bm, b, v, blk);		return dm_bm_read_lock(tm->bm, b, v, blk);
	}		}
	@@ -317,6 +384,12 @@ struct dm_block_manager dm_tm_get_bm(struct dm_transaction_manager tm)
	return tm->bm;		return tm->bm;
	}		}

			void dm_tm_issue_prefetches(struct dm_transaction_manager *tm)
			{
			prefetch_issue(&tm->prefetches, tm->bm);
			}
			EXPORT_SYMBOL_GPL(dm_tm_issue_prefetches);

	/----------------------------------------------------------------/		/----------------------------------------------------------------/

	static int dm_tm_create_internal(struct dm_block_manager *bm,		static int dm_tm_create_internal(struct dm_block_manager *bm,

drivers/md/persistent-data/dm-transaction-manager.h

+7 −0

Original line number	Original line	Diff line number	Diff line
	@@ -108,6 +108,13 @@ int dm_tm_ref(struct dm_transaction_manager *tm, dm_block_t b,

	struct dm_block_manager dm_tm_get_bm(struct dm_transaction_manager tm);		struct dm_block_manager dm_tm_get_bm(struct dm_transaction_manager tm);

			/*
			* If you're using a non-blocking clone the tm will build up a list of
			* requested blocks that weren't in core. This call will request those
			* blocks to be prefetched.
			*/
			void dm_tm_issue_prefetches(struct dm_transaction_manager *tm);

	/*		/*
	* A little utility that ties the knot by producing a transaction manager		* A little utility that ties the knot by producing a transaction manager
	* that has a space map managed by the transaction manager...		* that has a space map managed by the transaction manager...