Commit 532906aa authored by Joe Thornber's avatar Joe Thornber Committed by Mike Snitzer
Browse files

dm cache: add remove_cblock method to policy interface 



Implement policy_remove_cblock() and add remove_cblock method to the mq
policy.  These methods will be used by the following cache block
invalidation patch which adds the 'invalidate_cblocks' message to the
cache core.

Also, update some comments in dm-cache-policy.h

Signed-off-by: default avatarJoe Thornber <ejt@redhat.com>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
parent 633618e3

drivers/md/dm-cache-policy-internal.h

+5 −0
Original line number Diff line number Diff line
@@ -64,6 +64,11 @@ static inline void policy_remove_mapping(struct dm_cache_policy *p, dm_oblock_t 
	p->remove_mapping(p, oblock);

}



static inline int policy_remove_cblock(struct dm_cache_policy *p, dm_cblock_t cblock)

{

	return p->remove_cblock(p, cblock);

}



static inline void policy_force_mapping(struct dm_cache_policy *p,

					dm_oblock_t current_oblock, dm_oblock_t new_oblock)

{

drivers/md/dm-cache-policy-mq.c

+35 −0
Original line number Diff line number Diff line
@@ -304,6 +304,15 @@ static void free_entry(struct entry_pool *ep, struct entry *e) 
	list_add(&e->list, &ep->free);

}



/*

 * Returns NULL if the entry is free.

 */

static struct entry *epool_find(struct entry_pool *ep, dm_cblock_t cblock)

{

	struct entry *e = ep->entries + from_cblock(cblock);

	return e->hlist.pprev ? e : NULL;

}



static bool epool_empty(struct entry_pool *ep)

{

	return list_empty(&ep->free);
@@ -1020,6 +1029,31 @@ static void mq_remove_mapping(struct dm_cache_policy *p, dm_oblock_t oblock) 
	mutex_unlock(&mq->lock);

}



static int __remove_cblock(struct mq_policy *mq, dm_cblock_t cblock)

{

	struct entry *e = epool_find(&mq->cache_pool, cblock);



	if (!e)

		return -ENODATA;



	del(mq, e);

	free_entry(&mq->cache_pool, e);



	return 0;

}



static int mq_remove_cblock(struct dm_cache_policy *p, dm_cblock_t cblock)

{

	int r;

	struct mq_policy *mq = to_mq_policy(p);



	mutex_lock(&mq->lock);

	r = __remove_cblock(mq, cblock);

	mutex_unlock(&mq->lock);



	return r;

}



static int __mq_writeback_work(struct mq_policy *mq, dm_oblock_t *oblock,

			      dm_cblock_t *cblock)

{
@@ -1139,6 +1173,7 @@ static void init_policy_functions(struct mq_policy *mq) 
	mq->policy.load_mapping = mq_load_mapping;

	mq->policy.walk_mappings = mq_walk_mappings;

	mq->policy.remove_mapping = mq_remove_mapping;

	mq->policy.remove_cblock = mq_remove_cblock;

	mq->policy.writeback_work = mq_writeback_work;

	mq->policy.force_mapping = mq_force_mapping;

	mq->policy.residency = mq_residency;

drivers/md/dm-cache-policy.h

+17 −4
Original line number Diff line number Diff line
@@ -135,9 +135,6 @@ struct dm_cache_policy { 
	 */

	int (*lookup)(struct dm_cache_policy *p, dm_oblock_t oblock, dm_cblock_t *cblock);



	/*

	 * oblock must be a mapped block.  Must not block.

	 */

	void (*set_dirty)(struct dm_cache_policy *p, dm_oblock_t oblock);

	void (*clear_dirty)(struct dm_cache_policy *p, dm_oblock_t oblock);
@@ -159,8 +156,24 @@ struct dm_cache_policy { 
	void (*force_mapping)(struct dm_cache_policy *p, dm_oblock_t current_oblock,

			      dm_oblock_t new_oblock);



	int (*writeback_work)(struct dm_cache_policy *p, dm_oblock_t *oblock, dm_cblock_t *cblock);

	/*

	 * This is called via the invalidate_cblocks message.  It is

	 * possible the particular cblock has already been removed due to a

	 * write io in passthrough mode.  In which case this should return

	 * -ENODATA.

	 */

	int (*remove_cblock)(struct dm_cache_policy *p, dm_cblock_t cblock);



	/*

	 * Provide a dirty block to be written back by the core target.

	 *

	 * Returns:

	 *

	 * 0 and @cblock,@oblock: block to write back provided

	 *

	 * -ENODATA: no dirty blocks available

	 */

	int (*writeback_work)(struct dm_cache_policy *p, dm_oblock_t *oblock, dm_cblock_t *cblock);



	/*

	 * How full is the cache?

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