diff options
Diffstat (limited to 'fs/mbcache.c')
| -rw-r--r-- | fs/mbcache.c | 38 |
1 files changed, 34 insertions, 4 deletions
diff --git a/fs/mbcache.c b/fs/mbcache.c index 903be151dcfe..eccda3a02de6 100644 --- a/fs/mbcache.c +++ b/fs/mbcache.c @@ -63,13 +63,14 @@ static inline struct hlist_bl_head *mb_cache_entry_head(struct mb_cache *cache, * @mask - gfp mask with which the entry should be allocated * @key - key of the entry * @block - block that contains data + * @reusable - is the block reusable by other inodes? * * Creates entry in @cache with key @key and records that data is stored in * block @block. The function returns -EBUSY if entry with the same key * and for the same block already exists in cache. Otherwise 0 is returned. */ int mb_cache_entry_create(struct mb_cache *cache, gfp_t mask, u32 key, - sector_t block) + sector_t block, bool reusable) { struct mb_cache_entry *entry, *dup; struct hlist_bl_node *dup_node; @@ -91,6 +92,7 @@ int mb_cache_entry_create(struct mb_cache *cache, gfp_t mask, u32 key, atomic_set(&entry->e_refcnt, 1); entry->e_key = key; entry->e_block = block; + entry->e_reusable = reusable; head = mb_cache_entry_head(cache, key); hlist_bl_lock(head); hlist_bl_for_each_entry(dup, dup_node, head, e_hash_list) { @@ -137,7 +139,7 @@ static struct mb_cache_entry *__entry_find(struct mb_cache *cache, while (node) { entry = hlist_bl_entry(node, struct mb_cache_entry, e_hash_list); - if (entry->e_key == key) { + if (entry->e_key == key && entry->e_reusable) { atomic_inc(&entry->e_refcnt); goto out; } @@ -184,10 +186,38 @@ struct mb_cache_entry *mb_cache_entry_find_next(struct mb_cache *cache, } EXPORT_SYMBOL(mb_cache_entry_find_next); +/* + * mb_cache_entry_get - get a cache entry by block number (and key) + * @cache - cache we work with + * @key - key of block number @block + * @block - block number + */ +struct mb_cache_entry *mb_cache_entry_get(struct mb_cache *cache, u32 key, + sector_t block) +{ + struct hlist_bl_node *node; + struct hlist_bl_head *head; + struct mb_cache_entry *entry; + + head = mb_cache_entry_head(cache, key); + hlist_bl_lock(head); + hlist_bl_for_each_entry(entry, node, head, e_hash_list) { + if (entry->e_key == key && entry->e_block == block) { + atomic_inc(&entry->e_refcnt); + goto out; + } + } + entry = NULL; +out: + hlist_bl_unlock(head); + return entry; +} +EXPORT_SYMBOL(mb_cache_entry_get); + /* mb_cache_entry_delete_block - remove information about block from cache * @cache - cache we work with - * @key - key of the entry to remove - * @block - block containing data for @key + * @key - key of block @block + * @block - block number * * Remove entry from cache @cache with key @key with data stored in @block. */ |