diff options
Diffstat (limited to 'block/qcow2-cache.c')
| -rw-r--r-- | block/qcow2-cache.c | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/block/qcow2-cache.c b/block/qcow2-cache.c index f63e7d8e70..8457458418 100644 --- a/block/qcow2-cache.c +++ b/block/qcow2-cache.c @@ -49,6 +49,7 @@ struct Qcow2Cache { bool depends_on_flush; void *table_array; uint64_t lru_counter; + uint64_t cache_clean_lru_counter; }; static inline void *qcow2_cache_get_table_addr(BlockDriverState *bs, @@ -84,6 +85,40 @@ static void qcow2_cache_table_release(BlockDriverState *bs, Qcow2Cache *c, #endif } +static inline bool can_clean_entry(Qcow2Cache *c, int i) +{ + Qcow2CachedTable *t = &c->entries[i]; + return t->ref == 0 && !t->dirty && t->offset != 0 && + t->lru_counter <= c->cache_clean_lru_counter; +} + +void qcow2_cache_clean_unused(BlockDriverState *bs, Qcow2Cache *c) +{ + int i = 0; + while (i < c->size) { + int to_clean = 0; + + /* Skip the entries that we don't need to clean */ + while (i < c->size && !can_clean_entry(c, i)) { + i++; + } + + /* And count how many we can clean in a row */ + while (i < c->size && can_clean_entry(c, i)) { + c->entries[i].offset = 0; + c->entries[i].lru_counter = 0; + i++; + to_clean++; + } + + if (to_clean > 0) { + qcow2_cache_table_release(bs, c, i - to_clean, to_clean); + } + } + + c->cache_clean_lru_counter = c->lru_counter; +} + Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int num_tables) { BDRVQcowState *s = bs->opaque; |