dm mpath: check if scsi_dh module already loaded before trying to load
[zen-stable.git] / fs / xfs / xfs_mru_cache.h
blob36dd3ec8b4eb17fdbdf83dfd8496e46a1409c30b
1 /*
2 * Copyright (c) 2006-2007 Silicon Graphics, Inc.
3 * All Rights Reserved.
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
18 #ifndef __XFS_MRU_CACHE_H__
19 #define __XFS_MRU_CACHE_H__
22 /* Function pointer type for callback to free a client's data pointer. */
23 typedef void (*xfs_mru_cache_free_func_t)(unsigned long, void*);
25 typedef struct xfs_mru_cache
27 struct radix_tree_root store; /* Core storage data structure. */
28 struct list_head *lists; /* Array of lists, one per grp. */
29 struct list_head reap_list; /* Elements overdue for reaping. */
30 spinlock_t lock; /* Lock to protect this struct. */
31 unsigned int grp_count; /* Number of discrete groups. */
32 unsigned int grp_time; /* Time period spanned by grps. */
33 unsigned int lru_grp; /* Group containing time zero. */
34 unsigned long time_zero; /* Time first element was added. */
35 xfs_mru_cache_free_func_t free_func; /* Function pointer for freeing. */
36 struct delayed_work work; /* Workqueue data for reaping. */
37 unsigned int queued; /* work has been queued */
38 } xfs_mru_cache_t;
40 int xfs_mru_cache_init(void);
41 void xfs_mru_cache_uninit(void);
42 int xfs_mru_cache_create(struct xfs_mru_cache **mrup, unsigned int lifetime_ms,
43 unsigned int grp_count,
44 xfs_mru_cache_free_func_t free_func);
45 void xfs_mru_cache_destroy(struct xfs_mru_cache *mru);
46 int xfs_mru_cache_insert(struct xfs_mru_cache *mru, unsigned long key,
47 void *value);
48 void * xfs_mru_cache_remove(struct xfs_mru_cache *mru, unsigned long key);
49 void xfs_mru_cache_delete(struct xfs_mru_cache *mru, unsigned long key);
50 void *xfs_mru_cache_lookup(struct xfs_mru_cache *mru, unsigned long key);
51 void xfs_mru_cache_done(struct xfs_mru_cache *mru);
53 #endif /* __XFS_MRU_CACHE_H__ */