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authorTahsin Erdogan <tahsin@google.com>2017-06-22 10:29:53 -0400
committerTheodore Ts'o <tytso@mit.edu>2017-06-22 10:29:53 -0400
commitc07dfcb45877fbc6798fa042bab3c4b85378efd4 (patch)
treea626ee2c0841dd7370097b8a1e874941f34de4eb /fs/mbcache.c
parentb6d9029df083c0a9ce1d4eda1480105e635e0d61 (diff)
downloadlinux-stericsson-c07dfcb45877fbc6798fa042bab3c4b85378efd4.tar.gz
mbcache: make mbcache naming more generic
Make names more generic so that mbcache usage is not limited to block sharing. In a subsequent patch in the series ("ext4: xattr inode deduplication"), we start using the mbcache code for sharing xattr inodes. With that patch, old mb_cache_entry.e_block field could be holding either a block number or an inode number. Signed-off-by: Tahsin Erdogan <tahsin@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/mbcache.c')
-rw-r--r--fs/mbcache.c43
1 files changed, 21 insertions, 22 deletions
diff --git a/fs/mbcache.c b/fs/mbcache.c
index b19be429d655..45a8d52dc991 100644
--- a/fs/mbcache.c
+++ b/fs/mbcache.c
@@ -10,7 +10,7 @@
/*
* Mbcache is a simple key-value store. Keys need not be unique, however
* key-value pairs are expected to be unique (we use this fact in
- * mb_cache_entry_delete_block()).
+ * mb_cache_entry_delete()).
*
* Ext2 and ext4 use this cache for deduplication of extended attribute blocks.
* They use hash of a block contents as a key and block number as a value.
@@ -62,15 +62,15 @@ static inline struct hlist_bl_head *mb_cache_entry_head(struct mb_cache *cache,
* @cache - cache where the entry should be created
* @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?
+ * @value - value of the entry
+ * @reusable - is the entry reusable by others?
*
- * 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.
+ * Creates entry in @cache with key @key and value @value. The function returns
+ * -EBUSY if entry with the same key and value 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, bool reusable)
+ u64 value, bool reusable)
{
struct mb_cache_entry *entry, *dup;
struct hlist_bl_node *dup_node;
@@ -91,12 +91,12 @@ int mb_cache_entry_create(struct mb_cache *cache, gfp_t mask, u32 key,
/* One ref for hash, one ref returned */
atomic_set(&entry->e_refcnt, 1);
entry->e_key = key;
- entry->e_block = block;
+ entry->e_value = value;
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) {
- if (dup->e_key == key && dup->e_block == block) {
+ if (dup->e_key == key && dup->e_value == value) {
hlist_bl_unlock(head);
kmem_cache_free(mb_entry_cache, entry);
return -EBUSY;
@@ -187,13 +187,13 @@ 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)
+ * mb_cache_entry_get - get a cache entry by value (and key)
* @cache - cache we work with
- * @key - key of block number @block
- * @block - block number
+ * @key - key
+ * @value - value
*/
struct mb_cache_entry *mb_cache_entry_get(struct mb_cache *cache, u32 key,
- sector_t block)
+ u64 value)
{
struct hlist_bl_node *node;
struct hlist_bl_head *head;
@@ -202,7 +202,7 @@ struct mb_cache_entry *mb_cache_entry_get(struct mb_cache *cache, u32 key,
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) {
+ if (entry->e_key == key && entry->e_value == value) {
atomic_inc(&entry->e_refcnt);
goto out;
}
@@ -214,15 +214,14 @@ out:
}
EXPORT_SYMBOL(mb_cache_entry_get);
-/* mb_cache_entry_delete_block - remove information about block from cache
+/* mb_cache_entry_delete - remove a cache entry
* @cache - cache we work with
- * @key - key of block @block
- * @block - block number
+ * @key - key
+ * @value - value
*
- * Remove entry from cache @cache with key @key with data stored in @block.
+ * Remove entry from cache @cache with key @key and value @value.
*/
-void mb_cache_entry_delete_block(struct mb_cache *cache, u32 key,
- sector_t block)
+void mb_cache_entry_delete(struct mb_cache *cache, u32 key, u64 value)
{
struct hlist_bl_node *node;
struct hlist_bl_head *head;
@@ -231,7 +230,7 @@ void mb_cache_entry_delete_block(struct mb_cache *cache, u32 key,
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) {
+ if (entry->e_key == key && entry->e_value == value) {
/* We keep hash list reference to keep entry alive */
hlist_bl_del_init(&entry->e_hash_list);
hlist_bl_unlock(head);
@@ -248,7 +247,7 @@ void mb_cache_entry_delete_block(struct mb_cache *cache, u32 key,
}
hlist_bl_unlock(head);
}
-EXPORT_SYMBOL(mb_cache_entry_delete_block);
+EXPORT_SYMBOL(mb_cache_entry_delete);
/* mb_cache_entry_touch - cache entry got used
* @cache - cache the entry belongs to