xfs: embedd mru_elem into parent structure

There is no need to do a separate allocation for each mru element, just
embedd the structure into the parent one in the user.  Besides saving
a memory allocation and the infrastructure required for it this also
simplifies the API.

While we do major surgery on xfs_mru_cache.c also de-typedef it and
make struct mru_cache private to the implementation file.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

1 files changed, 12 insertions, 19 deletions

diff --git a/fs/xfs/xfs_mru_cache.h b/fs/xfs/xfs_mru_cache.h
index 36dd3ec8b4eb..fb5245ba5ff7 100644
--- a/fs/xfs/xfs_mru_cache.h
+++ b/fs/xfs/xfs_mru_cache.h
@@ -18,24 +18,15 @@
 #ifndef __XFS_MRU_CACHE_H__
 #define __XFS_MRU_CACHE_H__
 
+struct xfs_mru_cache;
 
-/* Function pointer type for callback to free a client's data pointer. */
-typedef void (*xfs_mru_cache_free_func_t)(unsigned long, void*);
+struct xfs_mru_cache_elem {
+	struct list_head list_node;
+	unsigned long	key;
+};
 
-typedef struct xfs_mru_cache
-{
-	struct radix_tree_root	store;     /* Core storage data structure.  */
-	struct list_head	*lists;    /* Array of lists, one per grp.  */
-	struct list_head	reap_list; /* Elements overdue for reaping. */
-	spinlock_t		lock;      /* Lock to protect this struct.  */
-	unsigned int		grp_count; /* Number of discrete groups.    */
-	unsigned int		grp_time;  /* Time period spanned by grps.  */
-	unsigned int		lru_grp;   /* Group containing time zero.   */
-	unsigned long		time_zero; /* Time first element was added. */
-	xfs_mru_cache_free_func_t free_func; /* Function pointer for freeing. */
-	struct delayed_work	work;      /* Workqueue data for reaping.   */
-	unsigned int		queued;	   /* work has been queued */
-} xfs_mru_cache_t;
+/* Function pointer type for callback to free a client's data pointer. */
+typedef void (*xfs_mru_cache_free_func_t)(struct xfs_mru_cache_elem *elem);
 
 int xfs_mru_cache_init(void);
 void xfs_mru_cache_uninit(void);
@@ -44,10 +35,12 @@ int xfs_mru_cache_create(struct xfs_mru_cache **mrup, unsigned int lifetime_ms,
 			     xfs_mru_cache_free_func_t free_func);
 void xfs_mru_cache_destroy(struct xfs_mru_cache *mru);
 int xfs_mru_cache_insert(struct xfs_mru_cache *mru, unsigned long key,
-				void *value);
-void * xfs_mru_cache_remove(struct xfs_mru_cache *mru, unsigned long key);
+		struct xfs_mru_cache_elem *elem);
+struct xfs_mru_cache_elem *
+xfs_mru_cache_remove(struct xfs_mru_cache *mru, unsigned long key);
 void xfs_mru_cache_delete(struct xfs_mru_cache *mru, unsigned long key);
-void *xfs_mru_cache_lookup(struct xfs_mru_cache *mru, unsigned long key);
+struct xfs_mru_cache_elem *
+xfs_mru_cache_lookup(struct xfs_mru_cache *mru, unsigned long key);
 void xfs_mru_cache_done(struct xfs_mru_cache *mru);
 
 #endif /* __XFS_MRU_CACHE_H__ */