LXR linux/fs/9p/cache.h

   1/*
   2 * V9FS cache definitions.
   3 *
   4 *  Copyright (C) 2009 by Abhishek Kulkarni <adkulkar@umail.iu.edu>
   5 *
   6 *  This program is free software; you can redistribute it and/or modify
   7 *  it under the terms of the GNU General Public License version 2
   8 *  as published by the Free Software Foundation.
   9 *
  10 *  This program is distributed in the hope that it will be useful,
  11 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 *  GNU General Public License for more details.
  14 *
  15 *  You should have received a copy of the GNU General Public License
  16 *  along with this program; if not, write to:
  17 *  Free Software Foundation
  18 *  51 Franklin Street, Fifth Floor
  19 *  Boston, MA  02111-1301  USA
  20 *
  21 */
  22
  23#ifndef _9P_CACHE_H
  24#ifdef CONFIG_9P_FSCACHE
  25#include <linux/fscache.h>
  26#include <linux/spinlock.h>
  27
  28extern struct kmem_cache *vcookie_cache;
  29
  30struct v9fs_cookie {
  31        spinlock_t lock;
  32        struct inode inode;
  33        struct fscache_cookie *fscache;
  34        struct p9_qid *qid;
  35};
  36
  37static inline struct v9fs_cookie *v9fs_inode2cookie(const struct inode *inode)
  38{
  39        return container_of(inode, struct v9fs_cookie, inode);
  40}
  41
  42extern struct fscache_netfs v9fs_cache_netfs;
  43extern const struct fscache_cookie_def v9fs_cache_session_index_def;
  44extern const struct fscache_cookie_def v9fs_cache_inode_index_def;
  45
  46extern void v9fs_cache_session_get_cookie(struct v9fs_session_info *v9ses);
  47extern void v9fs_cache_session_put_cookie(struct v9fs_session_info *v9ses);
  48
  49extern void v9fs_cache_inode_get_cookie(struct inode *inode);
  50extern void v9fs_cache_inode_put_cookie(struct inode *inode);
  51extern void v9fs_cache_inode_flush_cookie(struct inode *inode);
  52extern void v9fs_cache_inode_set_cookie(struct inode *inode, struct file *filp);
  53extern void v9fs_cache_inode_reset_cookie(struct inode *inode);
  54
  55extern int __v9fs_cache_register(void);
  56extern void __v9fs_cache_unregister(void);
  57
  58extern int __v9fs_fscache_release_page(struct page *page, gfp_t gfp);
  59extern void __v9fs_fscache_invalidate_page(struct page *page);
  60extern int __v9fs_readpage_from_fscache(struct inode *inode,
  61                                        struct page *page);
  62extern int __v9fs_readpages_from_fscache(struct inode *inode,
  63                                         struct address_space *mapping,
  64                                         struct list_head *pages,
  65                                         unsigned *nr_pages);
  66extern void __v9fs_readpage_to_fscache(struct inode *inode, struct page *page);
  67
  68
  69/**
  70 * v9fs_cache_register - Register v9fs file system with the cache
  71 */
  72static inline int v9fs_cache_register(void)
  73{
  74        return __v9fs_cache_register();
  75}
  76
  77/**
  78 * v9fs_cache_unregister - Unregister v9fs from the cache
  79 */
  80static inline void v9fs_cache_unregister(void)
  81{
  82        __v9fs_cache_unregister();
  83}
  84
  85static inline int v9fs_fscache_release_page(struct page *page,
  86                                            gfp_t gfp)
  87{
  88        return __v9fs_fscache_release_page(page, gfp);
  89}
  90
  91static inline void v9fs_fscache_invalidate_page(struct page *page)
  92{
  93        __v9fs_fscache_invalidate_page(page);
  94}
  95
  96static inline int v9fs_readpage_from_fscache(struct inode *inode,
  97                                             struct page *page)
  98{
  99        return __v9fs_readpage_from_fscache(inode, page);
 100}
 101
 102static inline int v9fs_readpages_from_fscache(struct inode *inode,
 103                                              struct address_space *mapping,
 104                                              struct list_head *pages,
 105                                              unsigned *nr_pages)
 106{
 107        return __v9fs_readpages_from_fscache(inode, mapping, pages,
 108                                             nr_pages);
 109}
 110
 111static inline void v9fs_readpage_to_fscache(struct inode *inode,
 112                                            struct page *page)
 113{
 114        if (PageFsCache(page))
 115                __v9fs_readpage_to_fscache(inode, page);
 116}
 117
 118static inline void v9fs_uncache_page(struct inode *inode, struct page *page)
 119{
 120        struct v9fs_cookie *vcookie = v9fs_inode2cookie(inode);
 121        fscache_uncache_page(vcookie->fscache, page);
 122        BUG_ON(PageFsCache(page));
 123}
 124
 125static inline void v9fs_vcookie_set_qid(struct inode *inode,
 126                                        struct p9_qid *qid)
 127{
 128        struct v9fs_cookie *vcookie = v9fs_inode2cookie(inode);
 129        spin_lock(&vcookie->lock);
 130        vcookie->qid = qid;
 131        spin_unlock(&vcookie->lock);
 132}
 133
 134#else /* CONFIG_9P_FSCACHE */
 135
 136static inline int v9fs_cache_register(void)
 137{
 138        return 1;
 139}
 140
 141static inline void v9fs_cache_unregister(void) {}
 142
 143static inline int v9fs_fscache_release_page(struct page *page,
 144                                            gfp_t gfp) {
 145        return 1;
 146}
 147
 148static inline void v9fs_fscache_invalidate_page(struct page *page) {}
 149
 150static inline int v9fs_readpage_from_fscache(struct inode *inode,
 151                                             struct page *page)
 152{
 153        return -ENOBUFS;
 154}
 155
 156static inline int v9fs_readpages_from_fscache(struct inode *inode,
 157                                              struct address_space *mapping,
 158                                              struct list_head *pages,
 159                                              unsigned *nr_pages)
 160{
 161        return -ENOBUFS;
 162}
 163
 164static inline void v9fs_readpage_to_fscache(struct inode *inode,
 165                                            struct page *page)
 166{}
 167
 168static inline void v9fs_uncache_page(struct inode *inode, struct page *page)
 169{}
 170
 171static inline void v9fs_vcookie_set_qid(struct inode *inode,
 172                                        struct p9_qid *qid)
 173{}
 174
 175#endif /* CONFIG_9P_FSCACHE */
 176#endif /* _9P_CACHE_H */
 177