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: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
This commit is contained in:
Joe Thornber
2013-11-08 16:36:17 +00:00
committed by Mike Snitzer
parent 633618e335
commit 532906aa7f
3 changed files with 57 additions and 4 deletions

View File

@@ -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;