xref: /linux/fs/smb/client/fscache.h (revision 0678df8271820bcf8fb4f877129f05d68a237de4)
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 timespec64 ctime = inode_get_ctime(inode);
53 	struct timespec64 mtime = inode_get_mtime(inode);
54 
55 	memset(cd, 0, sizeof(*cd));
56 	cd->last_write_time_sec   = cpu_to_le64(mtime.tv_sec);
57 	cd->last_write_time_nsec  = cpu_to_le32(mtime.tv_nsec);
58 	cd->last_change_time_sec  = cpu_to_le64(ctime.tv_sec);
59 	cd->last_change_time_nsec = cpu_to_le32(ctime.tv_nsec);
60 }
61 
62 
63 static inline struct fscache_cookie *cifs_inode_cookie(struct inode *inode)
64 {
65 	return netfs_i_cookie(&CIFS_I(inode)->netfs);
66 }
67 
68 static inline void cifs_invalidate_cache(struct inode *inode, unsigned int flags)
69 {
70 	struct cifs_fscache_inode_coherency_data cd;
71 
72 	cifs_fscache_fill_coherency(inode, &cd);
73 	fscache_invalidate(cifs_inode_cookie(inode), &cd,
74 			   i_size_read(inode), flags);
75 }
76 
77 extern int __cifs_fscache_query_occupancy(struct inode *inode,
78 					  pgoff_t first, unsigned int nr_pages,
79 					  pgoff_t *_data_first,
80 					  unsigned int *_data_nr_pages);
81 
82 static inline int cifs_fscache_query_occupancy(struct inode *inode,
83 					       pgoff_t first, unsigned int nr_pages,
84 					       pgoff_t *_data_first,
85 					       unsigned int *_data_nr_pages)
86 {
87 	if (!cifs_inode_cookie(inode))
88 		return -ENOBUFS;
89 	return __cifs_fscache_query_occupancy(inode, first, nr_pages,
90 					      _data_first, _data_nr_pages);
91 }
92 
93 extern int __cifs_readpage_from_fscache(struct inode *pinode, struct page *ppage);
94 extern void __cifs_readahead_to_fscache(struct inode *pinode, loff_t pos, size_t len);
95 
96 
97 static inline int cifs_readpage_from_fscache(struct inode *inode,
98 					     struct page *page)
99 {
100 	if (cifs_inode_cookie(inode))
101 		return __cifs_readpage_from_fscache(inode, page);
102 	return -ENOBUFS;
103 }
104 
105 static inline void cifs_readahead_to_fscache(struct inode *inode,
106 					     loff_t pos, size_t len)
107 {
108 	if (cifs_inode_cookie(inode))
109 		__cifs_readahead_to_fscache(inode, pos, len);
110 }
111 
112 #else /* CONFIG_CIFS_FSCACHE */
113 static inline
114 void cifs_fscache_fill_coherency(struct inode *inode,
115 				 struct cifs_fscache_inode_coherency_data *cd)
116 {
117 }
118 
119 static inline int cifs_fscache_get_super_cookie(struct cifs_tcon *tcon) { return 0; }
120 static inline void cifs_fscache_release_super_cookie(struct cifs_tcon *tcon) {}
121 
122 static inline void cifs_fscache_get_inode_cookie(struct inode *inode) {}
123 static inline void cifs_fscache_release_inode_cookie(struct inode *inode) {}
124 static inline void cifs_fscache_unuse_inode_cookie(struct inode *inode, bool update) {}
125 static inline struct fscache_cookie *cifs_inode_cookie(struct inode *inode) { return NULL; }
126 static inline void cifs_invalidate_cache(struct inode *inode, unsigned int flags) {}
127 
128 static inline int cifs_fscache_query_occupancy(struct inode *inode,
129 					       pgoff_t first, unsigned int nr_pages,
130 					       pgoff_t *_data_first,
131 					       unsigned int *_data_nr_pages)
132 {
133 	*_data_first = ULONG_MAX;
134 	*_data_nr_pages = 0;
135 	return -ENOBUFS;
136 }
137 
138 static inline int
139 cifs_readpage_from_fscache(struct inode *inode, struct page *page)
140 {
141 	return -ENOBUFS;
142 }
143 
144 static inline
145 void cifs_readahead_to_fscache(struct inode *inode, loff_t pos, size_t len) {}
146 
147 #endif /* CONFIG_CIFS_FSCACHE */
148 
149 #endif /* _CIFS_FSCACHE_H */
150