1 files changed, 0 insertions, 359 deletions
diff --git a/fs/mbcache2.c b/fs/mbcache2.c
deleted file mode 100644
index 5c3e1a8c3..000000000
--- a/fs/mbcache2.c
+++ /dev/null
@@ -1,359 +0,0 @@
-#include <linux/spinlock.h>
-#include <linux/slab.h>
-#include <linux/list.h>
-#include <linux/list_bl.h>
-#include <linux/module.h>
-#include <linux/sched.h>
-#include <linux/mbcache2.h>
-
-/*
- * 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
- * mb2_cache_entry_delete_block()).
- *
- * 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.
- * That's why keys need not be unique (different xattr blocks may end up having
- * the same hash). However block number always uniquely identifies a cache
- * entry.
- *
- * We provide functions for creation and removal of entries, search by key,
- * and a special "delete entry with given key-value pair" operation. Fixed
- * size hash table is used for fast key lookups.
- */
-
-struct mb2_cache {
-	/* Hash table of entries */
-	struct hlist_bl_head	*c_hash;
-	/* log2 of hash table size */
-	int			c_bucket_bits;
-	/* Protects c_lru_list, c_entry_count */
-	spinlock_t		c_lru_list_lock;
-	struct list_head	c_lru_list;
-	/* Number of entries in cache */
-	unsigned long		c_entry_count;
-	struct shrinker		c_shrink;
-};
-
-static struct kmem_cache *mb2_entry_cache;
-
-/*
- * mb2_cache_entry_create - create entry in 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
- *
- * 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 mb2_cache_entry_create(struct mb2_cache *cache, gfp_t mask, u32 key,
-			   sector_t block)
-{
-	struct mb2_cache_entry *entry, *dup;
-	struct hlist_bl_node *dup_node;
-	struct hlist_bl_head *head;
-
-	entry = kmem_cache_alloc(mb2_entry_cache, mask);
-	if (!entry)
-		return -ENOMEM;
-
-	INIT_LIST_HEAD(&entry->e_lru_list);
-	/* One ref for hash, one ref returned */
-	atomic_set(&entry->e_refcnt, 1);
-	entry->e_key = key;
-	entry->e_block = block;
-	head = &cache->c_hash[hash_32(key, cache->c_bucket_bits)];
-	entry->e_hash_list_head = head;
-	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) {
-			hlist_bl_unlock(head);
-			kmem_cache_free(mb2_entry_cache, entry);
-			return -EBUSY;
-		}
-	}
-	hlist_bl_add_head(&entry->e_hash_list, head);
-	hlist_bl_unlock(head);
-
-	spin_lock(&cache->c_lru_list_lock);
-	list_add_tail(&entry->e_lru_list, &cache->c_lru_list);
-	/* Grab ref for LRU list */
-	atomic_inc(&entry->e_refcnt);
-	cache->c_entry_count++;
-	spin_unlock(&cache->c_lru_list_lock);
-
-	return 0;
-}
-EXPORT_SYMBOL(mb2_cache_entry_create);
-
-void __mb2_cache_entry_free(struct mb2_cache_entry *entry)
-{
-	kmem_cache_free(mb2_entry_cache, entry);
-}
-EXPORT_SYMBOL(__mb2_cache_entry_free);
-
-static struct mb2_cache_entry *__entry_find(struct mb2_cache *cache,
-					    struct mb2_cache_entry *entry,
-					    u32 key)
-{
-	struct mb2_cache_entry *old_entry = entry;
-	struct hlist_bl_node *node;
-	struct hlist_bl_head *head;
-
-	if (entry)
-		head = entry->e_hash_list_head;
-	else
-		head = &cache->c_hash[hash_32(key, cache->c_bucket_bits)];
-	hlist_bl_lock(head);
-	if (entry && !hlist_bl_unhashed(&entry->e_hash_list))
-		node = entry->e_hash_list.next;
-	else
-		node = hlist_bl_first(head);
-	while (node) {
-		entry = hlist_bl_entry(node, struct mb2_cache_entry,
-				       e_hash_list);
-		if (entry->e_key == key) {
-			atomic_inc(&entry->e_refcnt);
-			goto out;
-		}
-		node = node->next;
-	}
-	entry = NULL;
-out:
-	hlist_bl_unlock(head);
-	if (old_entry)
-		mb2_cache_entry_put(cache, old_entry);
-
-	return entry;
-}
-
-/*
- * mb2_cache_entry_find_first - find the first entry in cache with given key
- * @cache: cache where we should search
- * @key: key to look for
- *
- * Search in @cache for entry with key @key. Grabs reference to the first
- * entry found and returns the entry.
- */
-struct mb2_cache_entry *mb2_cache_entry_find_first(struct mb2_cache *cache,
-						   u32 key)
-{
-	return __entry_find(cache, NULL, key);
-}
-EXPORT_SYMBOL(mb2_cache_entry_find_first);
-
-/*
- * mb2_cache_entry_find_next - find next entry in cache with the same
- * @cache: cache where we should search
- * @entry: entry to start search from
- *
- * Finds next entry in the hash chain which has the same key as @entry.
- * If @entry is unhashed (which can happen when deletion of entry races
- * with the search), finds the first entry in the hash chain. The function
- * drops reference to @entry and returns with a reference to the found entry.
- */
-struct mb2_cache_entry *mb2_cache_entry_find_next(struct mb2_cache *cache,
-						  struct mb2_cache_entry *entry)
-{
-	return __entry_find(cache, entry, entry->e_key);
-}
-EXPORT_SYMBOL(mb2_cache_entry_find_next);
-
-/* mb2_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
- *
- * Remove entry from cache @cache with key @key with data stored in @block.
- */
-void mb2_cache_entry_delete_block(struct mb2_cache *cache, u32 key,
-				  sector_t block)
-{
-	struct hlist_bl_node *node;
-	struct hlist_bl_head *head;
-	struct mb2_cache_entry *entry;
-
-	head = &cache->c_hash[hash_32(key, cache->c_bucket_bits)];
-	hlist_bl_lock(head);
-	hlist_bl_for_each_entry(entry, node, head, e_hash_list) {
-		if (entry->e_key == key && entry->e_block == block) {
-			/* We keep hash list reference to keep entry alive */
-			hlist_bl_del_init(&entry->e_hash_list);
-			hlist_bl_unlock(head);
-			spin_lock(&cache->c_lru_list_lock);
-			if (!list_empty(&entry->e_lru_list)) {
-				list_del_init(&entry->e_lru_list);
-				cache->c_entry_count--;
-				atomic_dec(&entry->e_refcnt);
-			}
-			spin_unlock(&cache->c_lru_list_lock);
-			mb2_cache_entry_put(cache, entry);
-			return;
-		}
-	}
-	hlist_bl_unlock(head);
-}
-EXPORT_SYMBOL(mb2_cache_entry_delete_block);
-
-/* mb2_cache_entry_touch - cache entry got used
- * @cache - cache the entry belongs to
- * @entry - entry that got used
- *
- * Move entry in lru list to reflect the fact that it was used.
- */
-void mb2_cache_entry_touch(struct mb2_cache *cache,
-			   struct mb2_cache_entry *entry)
-{
-	spin_lock(&cache->c_lru_list_lock);
-	if (!list_empty(&entry->e_lru_list))
-		list_move_tail(&cache->c_lru_list, &entry->e_lru_list);
-	spin_unlock(&cache->c_lru_list_lock);
-}
-EXPORT_SYMBOL(mb2_cache_entry_touch);
-
-static unsigned long mb2_cache_count(struct shrinker *shrink,
-				     struct shrink_control *sc)
-{
-	struct mb2_cache *cache = container_of(shrink, struct mb2_cache,
-					       c_shrink);
-
-	return cache->c_entry_count;
-}
-
-/* Shrink number of entries in cache */
-static unsigned long mb2_cache_scan(struct shrinker *shrink,
-				    struct shrink_control *sc)
-{
-	int nr_to_scan = sc->nr_to_scan;
-	struct mb2_cache *cache = container_of(shrink, struct mb2_cache,
-					      c_shrink);
-	struct mb2_cache_entry *entry;
-	struct hlist_bl_head *head;
-	unsigned int shrunk = 0;
-
-	spin_lock(&cache->c_lru_list_lock);
-	while (nr_to_scan-- && !list_empty(&cache->c_lru_list)) {
-		entry = list_first_entry(&cache->c_lru_list,
-					 struct mb2_cache_entry, e_lru_list);
-		list_del_init(&entry->e_lru_list);
-		cache->c_entry_count--;
-		/*
-		 * We keep LRU list reference so that entry doesn't go away
-		 * from under us.
-		 */
-		spin_unlock(&cache->c_lru_list_lock);
-		head = entry->e_hash_list_head;
-		hlist_bl_lock(head);
-		if (!hlist_bl_unhashed(&entry->e_hash_list)) {
-			hlist_bl_del_init(&entry->e_hash_list);
-			atomic_dec(&entry->e_refcnt);
-		}
-		hlist_bl_unlock(head);
-		if (mb2_cache_entry_put(cache, entry))
-			shrunk++;
-		cond_resched();
-		spin_lock(&cache->c_lru_list_lock);
-	}
-	spin_unlock(&cache->c_lru_list_lock);
-
-	return shrunk;
-}
-
-/*
- * mb2_cache_create - create cache
- * @bucket_bits: log2 of the hash table size
- *
- * Create cache for keys with 2^bucket_bits hash entries.
- */
-struct mb2_cache *mb2_cache_create(int bucket_bits)
-{
-	struct mb2_cache *cache;
-	int bucket_count = 1 << bucket_bits;
-	int i;
-
-	if (!try_module_get(THIS_MODULE))
-		return NULL;
-
-	cache = kzalloc(sizeof(struct mb2_cache), GFP_KERNEL);
-	if (!cache)
-		goto err_out;
-	cache->c_bucket_bits = bucket_bits;
-	INIT_LIST_HEAD(&cache->c_lru_list);
-	spin_lock_init(&cache->c_lru_list_lock);
-	cache->c_hash = kmalloc(bucket_count * sizeof(struct hlist_bl_head),
-				GFP_KERNEL);
-	if (!cache->c_hash) {
-		kfree(cache);
-		goto err_out;
-	}
-	for (i = 0; i < bucket_count; i++)
-		INIT_HLIST_BL_HEAD(&cache->c_hash[i]);
-
-	cache->c_shrink.count_objects = mb2_cache_count;
-	cache->c_shrink.scan_objects = mb2_cache_scan;
-	cache->c_shrink.seeks = DEFAULT_SEEKS;
-	register_shrinker(&cache->c_shrink);
-
-	return cache;
-
-err_out:
-	module_put(THIS_MODULE);
-	return NULL;
-}
-EXPORT_SYMBOL(mb2_cache_create);
-
-/*
- * mb2_cache_destroy - destroy cache
- * @cache: the cache to destroy
- *
- * Free all entries in cache and cache itself. Caller must make sure nobody
- * (except shrinker) can reach @cache when calling this.
- */
-void mb2_cache_destroy(struct mb2_cache *cache)
-{
-	struct mb2_cache_entry *entry, *next;
-
-	unregister_shrinker(&cache->c_shrink);
-
-	/*
-	 * We don't bother with any locking. Cache must not be used at this
-	 * point.
-	 */
-	list_for_each_entry_safe(entry, next, &cache->c_lru_list, e_lru_list) {
-		if (!hlist_bl_unhashed(&entry->e_hash_list)) {
-			hlist_bl_del_init(&entry->e_hash_list);
-			atomic_dec(&entry->e_refcnt);
-		} else
-			WARN_ON(1);
-		list_del(&entry->e_lru_list);
-		WARN_ON(atomic_read(&entry->e_refcnt) != 1);
-		mb2_cache_entry_put(cache, entry);
-	}
-	kfree(cache->c_hash);
-	kfree(cache);
-	module_put(THIS_MODULE);
-}
-EXPORT_SYMBOL(mb2_cache_destroy);
-
-static int __init mb2cache_init(void)
-{
-	mb2_entry_cache = kmem_cache_create("mbcache",
-				sizeof(struct mb2_cache_entry), 0,
-				SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD, NULL);
-	BUG_ON(!mb2_entry_cache);
-	return 0;
-}
-
-static void __exit mb2cache_exit(void)
-{
-	kmem_cache_destroy(mb2_entry_cache);
-}
-
-module_init(mb2cache_init)
-module_exit(mb2cache_exit)
-
-MODULE_AUTHOR("Jan Kara <jack@suse.cz>");
-MODULE_DESCRIPTION("Meta block cache (for extended attributes)");
-MODULE_LICENSE("GPL");