[sheepdog] [PATCH v2 3/6] object cache: clean up and fix cache size calculation

[Liu Yuan]

From: Liu Yuan <tailai...@taobao.com>

We need to subtrack the object for deletion.

Signed-off-by: Liu Yuan <tailai...@taobao.com>
---
 sheep/object_cache.c |   24 ++++++------------------
 1 file changed, 6 insertions(+), 18 deletions(-)

diff --git a/sheep/object_cache.c b/sheep/object_cache.c
index 2bbf0b0..19f83ae 100644
--- a/sheep/object_cache.c
+++ b/sheep/object_cache.c
@@ -46,6 +46,7 @@
 
 #define CACHE_BLOCK_SIZE      ((UINT64_C(1) << 10) * 64) /* 64 KB */
 
+#define CACHE_OBJECT_SIZE (SD_DATA_OBJ_SIZE / 1024 / 1024) /* M */
 
 struct global_cache {
        uint32_t cache_size;
@@ -460,7 +461,6 @@ static void do_reclaim(struct work *work)
 
        list_for_each_entry_revert_safe_rcu(entry, n,
                       &sys_cache.cache_lru_list, lru_list) {
-               unsigned data_length;
                /* Reclaim cache to 80% of max size */
                if (uatomic_read(&sys_cache.cache_size) <=
                        sys->object_cache_size * 8 / 10)
@@ -468,13 +468,7 @@ static void do_reclaim(struct work *work)
 
                if (do_reclaim_object(entry) < 0)
                        continue;
-               if (idx_has_vdi_bit(entry_idx(entry)))
-                       data_length = SD_INODE_SIZE;
-               else
-                       data_length = SD_DATA_OBJ_SIZE;
-
-               data_length = data_length / 1024 / 1024;
-               uatomic_sub(&sys_cache.cache_size, data_length);
+               uatomic_sub(&sys_cache.cache_size, CACHE_OBJECT_SIZE);
        }
 
        dprintf("cache reclaim complete\n");
@@ -560,16 +554,9 @@ void object_cache_try_to_reclaim(void)
 }
 
 static void add_to_object_cache(struct object_cache *oc, uint32_t idx,
-                               bool writeback)
+                               bool create)
 {
        struct object_cache_entry *entry, *old;
-       uint32_t data_length;
-
-       if (idx_has_vdi_bit(idx))
-               data_length = SD_INODE_SIZE;
-       else
-               data_length = SD_DATA_OBJ_SIZE;
-       data_length = data_length / 1024 / 1024;
 
        entry = xzalloc(sizeof(*entry));
        entry->oc = oc;
@@ -582,14 +569,14 @@ static void add_to_object_cache(struct object_cache *oc, 
uint32_t idx,
        old = object_cache_insert(&oc->object_tree, entry);
        if (!old) {
                dprintf("oid %"PRIx64"\n", idx_to_oid(oc->vid, idx));
-               uatomic_add(&sys_cache.cache_size, data_length);
+               uatomic_add(&sys_cache.cache_size, CACHE_OBJECT_SIZE);
                list_add(&entry->object_list, &oc->object_list);
                cds_list_add_rcu(&entry->lru_list, &sys_cache.cache_lru_list);
        } else {
                free(entry);
                entry = old;
        }
-       if (writeback) {
+       if (create) {
                entry->bmap = UINT64_MAX;
                entry->idx |= CACHE_CREATE_BIT;
                list_add(&entry->dirty_list, &oc->dirty_list);
@@ -804,6 +791,7 @@ void object_cache_delete(uint32_t vid)
        pthread_rwlock_wrlock(&cache->lock);
        list_for_each_entry_safe(entry, t, &cache->object_list, object_list) {
                del_from_object_tree_and_list(entry, &cache->object_tree);
+               uatomic_sub(&sys_cache.cache_size, CACHE_OBJECT_SIZE);
        }
        pthread_rwlock_unlock(&cache->lock);
        free(cache);
-- 
1.7.9.5

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