fs/cifs/fscache.h

   1 /*
   2  *   fs/cifs/fscache.h - CIFS filesystem cache interface definitions
   3  *
   4  *   Copyright (c) 2010 Novell, Inc.
   5  *   Authors(s): Suresh Jayaraman (sjayaraman@suse.de>
   6  *
   7  *   This library is free software; you can redistribute it and/or modify
   8  *   it under the terms of the GNU Lesser General Public License as published
   9  *   by the Free Software Foundation; either version 2.1 of the License, or
  10  *   (at your option) any later version.
  11  *
  12  *   This library is distributed in the hope that it will be useful,
  13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  15  *   the GNU Lesser General Public License for more details.
  16  *
  17  *   You should have received a copy of the GNU Lesser General Public License
  18  *   along with this library; if not, write to the Free Software
  19  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  20  */
  21 #ifndef _CIFS_FSCACHE_H
  22 #define _CIFS_FSCACHE_H
  23
  24 #include <linux/fscache.h>
  25
  26 #include "cifsglob.h"
  27
  28 #ifdef CONFIG_CIFS_FSCACHE
  29
  30 /*
  31  * Auxiliary data attached to CIFS superblock within the cache
  32  */
  33 struct cifs_fscache_super_auxdata {
  34         u64     resource_id;            /* unique server resource id */
  35         __le64  vol_create_time;
  36         u32     vol_serial_number;
  37 } __packed;
  38
  39 /*
  40  * Auxiliary data attached to CIFS inode within the cache
  41  */
  42 struct cifs_fscache_inode_auxdata {
  43         u64 last_write_time_sec;
  44         u64 last_change_time_sec;
  45         u32 last_write_time_nsec;
  46         u32 last_change_time_nsec;
  47         u64 eof;
  48 };
  49
  50 /*
  51  * cache.c
  52  */
  53 extern struct fscache_netfs cifs_fscache_netfs;
  54 extern const struct fscache_cookie_def cifs_fscache_server_index_def;
  55 extern const struct fscache_cookie_def cifs_fscache_super_index_def;
  56 extern const struct fscache_cookie_def cifs_fscache_inode_object_def;
  57
  58 extern int cifs_fscache_register(void);
  59 extern void cifs_fscache_unregister(void);
  60
  61 /*
  62  * fscache.c
  63  */
  64 extern void cifs_fscache_get_client_cookie(struct TCP_Server_Info *);
  65 extern void cifs_fscache_release_client_cookie(struct TCP_Server_Info *);
  66 extern void cifs_fscache_get_super_cookie(struct cifs_tcon *);
  67 extern void cifs_fscache_release_super_cookie(struct cifs_tcon *);
  68
  69 extern void cifs_fscache_release_inode_cookie(struct inode *);
  70 extern void cifs_fscache_set_inode_cookie(struct inode *, struct file *);
  71 extern void cifs_fscache_reset_inode_cookie(struct inode *);
  72
  73 extern void __cifs_fscache_invalidate_page(struct page *, struct inode *);
  74 extern int cifs_fscache_release_page(struct page *page, gfp_t gfp);
  75 extern int __cifs_readpage_from_fscache(struct inode *, struct page *);
  76 extern int __cifs_readpages_from_fscache(struct inode *,
  77                                          struct address_space *,
  78                                          struct list_head *,
  79                                          unsigned *);
  80 extern void __cifs_fscache_readpages_cancel(struct inode *, struct list_head *);
  81
  82 extern void __cifs_readpage_to_fscache(struct inode *, struct page *);
  83
  84 static inline void cifs_fscache_invalidate_page(struct page *page,
  85                                                struct inode *inode)
  86 {
  87         if (PageFsCache(page))
  88                 __cifs_fscache_invalidate_page(page, inode);
  89 }
  90
  91 static inline int cifs_readpage_from_fscache(struct inode *inode,
  92                                              struct page *page)
  93 {
  94         if (CIFS_I(inode)->fscache)
  95                 return __cifs_readpage_from_fscache(inode, page);
  96
  97         return -ENOBUFS;
  98 }
  99
 100 static inline int cifs_readpages_from_fscache(struct inode *inode,
 101                                               struct address_space *mapping,
 102                                               struct list_head *pages,
 103                                               unsigned *nr_pages)
 104 {
 105         if (CIFS_I(inode)->fscache)
 106                 return __cifs_readpages_from_fscache(inode, mapping, pages,
 107                                                      nr_pages);
 108         return -ENOBUFS;
 109 }
 110
 111 static inline void cifs_readpage_to_fscache(struct inode *inode,
 112                                             struct page *page)
 113 {
 114         if (PageFsCache(page))
 115                 __cifs_readpage_to_fscache(inode, page);
 116 }
 117
 118 static inline void cifs_fscache_readpages_cancel(struct inode *inode,
 119                                                  struct list_head *pages)
 120 {
 121         if (CIFS_I(inode)->fscache)
 122                 return __cifs_fscache_readpages_cancel(inode, pages);
 123 }
 124
 125 #else /* CONFIG_CIFS_FSCACHE */
 126 static inline int cifs_fscache_register(void) { return 0; }
 127 static inline void cifs_fscache_unregister(void) {}
 128
 129 static inline void
 130 cifs_fscache_get_client_cookie(struct TCP_Server_Info *server) {}
 131 static inline void
 132 cifs_fscache_release_client_cookie(struct TCP_Server_Info *server) {}
 133 static inline void cifs_fscache_get_super_cookie(struct cifs_tcon *tcon) {}
 134 static inline void
 135 cifs_fscache_release_super_cookie(struct cifs_tcon *tcon) {}
 136
 137 static inline void cifs_fscache_release_inode_cookie(struct inode *inode) {}
 138 static inline void cifs_fscache_set_inode_cookie(struct inode *inode,
 139                                                  struct file *filp) {}
 140 static inline void cifs_fscache_reset_inode_cookie(struct inode *inode) {}
 141 static inline int cifs_fscache_release_page(struct page *page, gfp_t gfp)
 142 {
 143         return 1; /* May release page */
 144 }
 145
 146 static inline void cifs_fscache_invalidate_page(struct page *page,
 147                         struct inode *inode) {}
 148 static inline int
 149 cifs_readpage_from_fscache(struct inode *inode, struct page *page)
 150 {
 151         return -ENOBUFS;
 152 }
 153
 154 static inline int cifs_readpages_from_fscache(struct inode *inode,
 155                                               struct address_space *mapping,
 156                                               struct list_head *pages,
 157                                               unsigned *nr_pages)
 158 {
 159         return -ENOBUFS;
 160 }
 161
 162 static inline void cifs_readpage_to_fscache(struct inode *inode,
 163                         struct page *page) {}
 164
 165 static inline void cifs_fscache_readpages_cancel(struct inode *inode,
 166                                                  struct list_head *pages)
 167 {
 168 }
 169
 170 #endif /* CONFIG_CIFS_FSCACHE */
 171
 172 #endif /* _CIFS_FSCACHE_H */