X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=fs%2Fmbcache.c;h=93444747237b98c03d5192870bd9740311da93f7;hb=40c73abbb37e399eba274fe49e520ffa3dd65bdb;hp=cf4e6cdfd15b5afc091c0f2a060af90450176811;hpb=6c74700fdb8e3bc34c31790384a8ec16c4fefd97;p=pandora-kernel.git

diff --git a/fs/mbcache.c b/fs/mbcache.c
index cf4e6cdfd15b..a25444ab2baf 100644
--- a/fs/mbcache.c
+++ b/fs/mbcache.c
@@ -76,17 +76,6 @@ EXPORT_SYMBOL(mb_cache_entry_find_first);
 EXPORT_SYMBOL(mb_cache_entry_find_next);
 #endif
 
-struct mb_cache {
-	struct list_head		c_cache_list;
-	const char			*c_name;
-	atomic_t			c_entry_count;
-	int				c_bucket_bits;
-	struct kmem_cache		*c_entry_cache;
-	struct list_head		*c_block_hash;
-	struct list_head		*c_index_hash;
-};
-
-
 /*
  * Global data: list of all mbcache's, lru list, and a spinlock for
  * accessing cache data structures on SMP machines. The lru list is
@@ -243,6 +232,12 @@ mb_cache_create(const char *name, int bucket_bits)
 	if (!cache->c_entry_cache)
 		goto fail2;
 
+	/*
+	 * Set an upper limit on the number of cache entries so that the hash
+	 * chains won't grow too long.
+	 */
+	cache->c_max_entries = bucket_count << 4;
+
 	spin_lock(&mb_cache_spinlock);
 	list_add(&cache->c_cache_list, &mb_cache_list);
 	spin_unlock(&mb_cache_spinlock);
@@ -333,7 +328,6 @@ mb_cache_destroy(struct mb_cache *cache)
 	kfree(cache);
 }
 
-
 /*
  * mb_cache_entry_alloc()
  *
@@ -345,17 +339,29 @@ mb_cache_destroy(struct mb_cache *cache)
 struct mb_cache_entry *
 mb_cache_entry_alloc(struct mb_cache *cache, gfp_t gfp_flags)
 {
-	struct mb_cache_entry *ce;
-
-	ce = kmem_cache_alloc(cache->c_entry_cache, gfp_flags);
-	if (ce) {
+	struct mb_cache_entry *ce = NULL;
+
+	if (atomic_read(&cache->c_entry_count) >= cache->c_max_entries) {
+		spin_lock(&mb_cache_spinlock);
+		if (!list_empty(&mb_cache_lru_list)) {
+			ce = list_entry(mb_cache_lru_list.next,
+					struct mb_cache_entry, e_lru_list);
+			list_del_init(&ce->e_lru_list);
+			__mb_cache_entry_unhash(ce);
+		}
+		spin_unlock(&mb_cache_spinlock);
+	}
+	if (!ce) {
+		ce = kmem_cache_alloc(cache->c_entry_cache, gfp_flags);
+		if (!ce)
+			return NULL;
 		atomic_inc(&cache->c_entry_count);
 		INIT_LIST_HEAD(&ce->e_lru_list);
 		INIT_LIST_HEAD(&ce->e_block_list);
 		ce->e_cache = cache;
-		ce->e_used = 1 + MB_CACHE_WRITER;
 		ce->e_queued = 0;
 	}
+	ce->e_used = 1 + MB_CACHE_WRITER;
 	return ce;
 }