xref: /linux/fs/smb/client/fscache.h (revision f2d14bc4e437b8ed21e6890ae047a6ec47c030d9)
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_readahead_to_fscache(struct inode *pinode, loff_t pos, size_t len);
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_readahead_to_fscache(struct inode *inode,
105 					     loff_t pos, size_t len)
106 {
107 	if (cifs_inode_cookie(inode))
108 		__cifs_readahead_to_fscache(inode, pos, len);
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_readahead_to_fscache(struct inode *inode, loff_t pos, size_t len) {}
145 
146 #endif /* CONFIG_CIFS_FSCACHE */
147 
148 #endif /* _CIFS_FSCACHE_H */
149