xref: /kernel/linux/linux-6.6/fs/smb/client/fscache.h (revision 62306a36)
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 */
20struct 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 */
29struct 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 */
41extern int cifs_fscache_get_super_cookie(struct cifs_tcon *);
42extern void cifs_fscache_release_super_cookie(struct cifs_tcon *);
43
44extern void cifs_fscache_get_inode_cookie(struct inode *inode);
45extern void cifs_fscache_release_inode_cookie(struct inode *);
46extern void cifs_fscache_unuse_inode_cookie(struct inode *inode, bool update);
47
48static inline
49void 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
63static inline struct fscache_cookie *cifs_inode_cookie(struct inode *inode)
64{
65	return netfs_i_cookie(&CIFS_I(inode)->netfs);
66}
67
68static 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
77extern 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
82static 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
93extern int __cifs_readpage_from_fscache(struct inode *pinode, struct page *ppage);
94extern void __cifs_readahead_to_fscache(struct inode *pinode, loff_t pos, size_t len);
95
96
97static 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
105static 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 */
113static inline
114void cifs_fscache_fill_coherency(struct inode *inode,
115				 struct cifs_fscache_inode_coherency_data *cd)
116{
117}
118
119static inline int cifs_fscache_get_super_cookie(struct cifs_tcon *tcon) { return 0; }
120static inline void cifs_fscache_release_super_cookie(struct cifs_tcon *tcon) {}
121
122static inline void cifs_fscache_get_inode_cookie(struct inode *inode) {}
123static inline void cifs_fscache_release_inode_cookie(struct inode *inode) {}
124static inline void cifs_fscache_unuse_inode_cookie(struct inode *inode, bool update) {}
125static inline struct fscache_cookie *cifs_inode_cookie(struct inode *inode) { return NULL; }
126static inline void cifs_invalidate_cache(struct inode *inode, unsigned int flags) {}
127
128static 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
138static inline int
139cifs_readpage_from_fscache(struct inode *inode, struct page *page)
140{
141	return -ENOBUFS;
142}
143
144static inline
145void 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