fs/cifs/fscache.h

   1 /* SPDX-License-Identifier: LGPL-2.1 */
   2 /*
   3  *   CIFS filesystem cache interface definitions
   4  *
   5  *   Copyright (c) 2010 Novell, Inc.
   6  *   Authors(s): Suresh Jayaraman (sjayaraman@suse.de>
   7  *
   8  */
   9 #ifndef _CIFS_FSCACHE_H
  10 #define _CIFS_FSCACHE_H
  11
  12 #include <linux/swap.h>
  13 #include <linux/fscache.h>
  14
  15 #include "cifsglob.h"
  16
  17 /*
  18  * Coherency data attached to CIFS volume within the cache
  19  */
  20 struct cifs_fscache_volume_coherency_data {
  21         __le64  resource_id;            /* unique server resource id */
  22         __le64  vol_create_time;
  23         __le32  vol_serial_number;
  24 } __packed;
  25
  26 /*
  27  * Coherency data attached to CIFS inode within the cache.
  28  */
  29 struct cifs_fscache_inode_coherency_data {
  30         __le64 last_write_time_sec;
  31         __le64 last_change_time_sec;
  32         __le32 last_write_time_nsec;
  33         __le32 last_change_time_nsec;
  34 };
  35
  36 #ifdef CONFIG_CIFS_FSCACHE
  37
  38 /*
  39  * fscache.c
  40  */
  41 extern int cifs_fscache_get_super_cookie(struct cifs_tcon *);
  42 extern void cifs_fscache_release_super_cookie(struct cifs_tcon *);
  43
  44 extern void cifs_fscache_get_inode_cookie(struct inode *inode);
  45 extern void cifs_fscache_release_inode_cookie(struct inode *);
  46 extern void cifs_fscache_unuse_inode_cookie(struct inode *inode, bool update);
  47
  48 static inline
  49 void cifs_fscache_fill_coherency(struct inode *inode,
  50                                  struct cifs_fscache_inode_coherency_data *cd)
  51 {
  52         struct cifsInodeInfo *cifsi = CIFS_I(inode);
  53
  54         memset(cd, 0, sizeof(*cd));
  55         cd->last_write_time_sec   = cpu_to_le64(cifsi->netfs.inode.i_mtime.tv_sec);
  56         cd->last_write_time_nsec  = cpu_to_le32(cifsi->netfs.inode.i_mtime.tv_nsec);
  57         cd->last_change_time_sec  = cpu_to_le64(cifsi->netfs.inode.i_ctime.tv_sec);
  58         cd->last_change_time_nsec = cpu_to_le32(cifsi->netfs.inode.i_ctime.tv_nsec);
  59 }
  60
  61
  62 static inline struct fscache_cookie *cifs_inode_cookie(struct inode *inode)
  63 {
  64         return netfs_i_cookie(&CIFS_I(inode)->netfs);
  65 }
  66
  67 static inline void cifs_invalidate_cache(struct inode *inode, unsigned int flags)
  68 {
  69         struct cifs_fscache_inode_coherency_data cd;
  70
  71         cifs_fscache_fill_coherency(inode, &cd);
  72         fscache_invalidate(cifs_inode_cookie(inode), &cd,
  73                            i_size_read(inode), flags);
  74 }
  75
  76 extern int __cifs_fscache_query_occupancy(struct inode *inode,
  77                                           pgoff_t first, unsigned int nr_pages,
  78                                           pgoff_t *_data_first,
  79                                           unsigned int *_data_nr_pages);
  80
  81 static inline int cifs_fscache_query_occupancy(struct inode *inode,
  82                                                pgoff_t first, unsigned int nr_pages,
  83                                                pgoff_t *_data_first,
  84                                                unsigned int *_data_nr_pages)
  85 {
  86         if (!cifs_inode_cookie(inode))
  87                 return -ENOBUFS;
  88         return __cifs_fscache_query_occupancy(inode, first, nr_pages,
  89                                               _data_first, _data_nr_pages);
  90 }
  91
  92 extern int __cifs_readpage_from_fscache(struct inode *pinode, struct page *ppage);
  93 extern void __cifs_readpage_to_fscache(struct inode *pinode, struct page *ppage);
  94
  95
  96 static inline int cifs_readpage_from_fscache(struct inode *inode,
  97                                              struct page *page)
  98 {
  99         if (cifs_inode_cookie(inode))
 100                 return __cifs_readpage_from_fscache(inode, page);
 101         return -ENOBUFS;
 102 }
 103
 104 static inline void cifs_readpage_to_fscache(struct inode *inode,
 105                                             struct page *page)
 106 {
 107         if (cifs_inode_cookie(inode))
 108                 __cifs_readpage_to_fscache(inode, page);
 109 }
 110
 111 #else /* CONFIG_CIFS_FSCACHE */
 112 static inline
 113 void cifs_fscache_fill_coherency(struct inode *inode,
 114                                  struct cifs_fscache_inode_coherency_data *cd)
 115 {
 116 }
 117
 118 static inline int cifs_fscache_get_super_cookie(struct cifs_tcon *tcon) { return 0; }
 119 static inline void cifs_fscache_release_super_cookie(struct cifs_tcon *tcon) {}
 120
 121 static inline void cifs_fscache_get_inode_cookie(struct inode *inode) {}
 122 static inline void cifs_fscache_release_inode_cookie(struct inode *inode) {}
 123 static inline void cifs_fscache_unuse_inode_cookie(struct inode *inode, bool update) {}
 124 static inline struct fscache_cookie *cifs_inode_cookie(struct inode *inode) { return NULL; }
 125 static inline void cifs_invalidate_cache(struct inode *inode, unsigned int flags) {}
 126
 127 static inline int cifs_fscache_query_occupancy(struct inode *inode,
 128                                                pgoff_t first, unsigned int nr_pages,
 129                                                pgoff_t *_data_first,
 130                                                unsigned int *_data_nr_pages)
 131 {
 132         *_data_first = ULONG_MAX;
 133         *_data_nr_pages = 0;
 134         return -ENOBUFS;
 135 }
 136
 137 static inline int
 138 cifs_readpage_from_fscache(struct inode *inode, struct page *page)
 139 {
 140         return -ENOBUFS;
 141 }
 142
 143 static inline
 144 void cifs_readpage_to_fscache(struct inode *inode, struct page *page) {}
 145
 146 #endif /* CONFIG_CIFS_FSCACHE */
 147
 148 #endif /* _CIFS_FSCACHE_H */