static void __remove_mapping(struct smq_policy *mq, dm_oblock_t oblock)
{
struct entry *e;
e = h_lookup(&mq->table, oblock);
BUG_ON(!e);
del(mq, e);
free_entry(&mq->cache_alloc, e);
}
static void __smq_set_clear_dirty(struct smq_policy *mq, dm_oblock_t oblock, bool set)
{
struct entry *e;
e = h_lookup(&mq->table, oblock);
BUG_ON(!e);
del(mq, e);
e->dirty = set;
push(mq, e);
}
static void __force_mapping(struct smq_policy *mq,
dm_oblock_t current_oblock, dm_oblock_t new_oblock)
{
struct entry *e = h_lookup(&mq->table, current_oblock);
if (e) {
del(mq, e);
e->oblock = new_oblock;
e->dirty = true;
push(mq, e);
}
}
static int smq_lookup(struct dm_cache_policy *p, dm_oblock_t oblock, dm_cblock_t *cblock)
{
int r;
unsigned long flags;
struct smq_policy *mq = to_smq_policy(p);
struct entry *e;
spin_lock_irqsave(&mq->lock, flags);
e = h_lookup(&mq->table, oblock);
if (e) {
*cblock = infer_cblock(mq, e);
r = 0;
} else
r = -ENOENT;
spin_unlock_irqrestore(&mq->lock, flags);
return r;
}
static int smq_lookup(struct dm_cache_policy *p, dm_oblock_t oblock, dm_cblock_t *cblock)
{
int r;
struct smq_policy *mq = to_smq_policy(p);
struct entry *e;
if (!mutex_trylock(&mq->lock))
return -EWOULDBLOCK;
e = h_lookup(&mq->table, oblock);
if (e) {
*cblock = infer_cblock(mq, e);
r = 0;
} else
r = -ENOENT;
mutex_unlock(&mq->lock);
return r;
}
static struct entry *update_hotspot_queue(struct smq_policy *mq, dm_oblock_t b, struct bio *bio)
{
unsigned hi;
dm_oblock_t hb = to_hblock(mq, b);
struct entry *e = h_lookup(&mq->hotspot_table, hb);
if (e) {
stats_level_accessed(&mq->hotspot_stats, e->level);
hi = get_index(&mq->hotspot_alloc, e);
q_requeue(&mq->hotspot, e,
test_and_set_bit(hi, mq->hotspot_hit_bits) ?
0u : mq->hotspot_level_jump);
} else {
stats_miss(&mq->hotspot_stats);
e = alloc_entry(&mq->hotspot_alloc);
if (!e) {
e = q_pop(&mq->hotspot);
if (e) {
h_remove(&mq->hotspot_table, e);
hi = get_index(&mq->hotspot_alloc, e);
clear_bit(hi, mq->hotspot_hit_bits);
}
}
if (e) {
e->oblock = hb;
q_push(&mq->hotspot, e);
h_insert(&mq->hotspot_table, e);
}
}
return e;
}
/*
* Looks the oblock up in the hash table, then decides whether to put in
* pre_cache, or cache etc.
*/
static int map(struct smq_policy *mq, struct bio *bio, dm_oblock_t oblock,
bool can_migrate, bool fast_promote,
struct policy_locker *locker, struct policy_result *result)
{
struct entry *e, *hs_e;
enum promote_result pr;
hs_e = update_hotspot_queue(mq, oblock, bio);
e = h_lookup(&mq->table, oblock);
if (e) {
stats_level_accessed(&mq->cache_stats, e->level);
requeue(mq, e);
result->op = POLICY_HIT;
result->cblock = infer_cblock(mq, e);
} else {
stats_miss(&mq->cache_stats);
pr = should_promote(mq, hs_e, bio, fast_promote);
if (pr == PROMOTE_NOT)
result->op = POLICY_MISS;
else {
if (!can_migrate) {
result->op = POLICY_MISS;
return -EWOULDBLOCK;
}
insert_in_cache(mq, oblock, locker, result, pr);
}
}
return 0;
}
