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1/* NFS filesystem cache interface definitions
2 *
3 * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public Licence
8 * as published by the Free Software Foundation; either version
9 * 2 of the Licence, or (at your option) any later version.
10 */
11
12#ifndef _NFS_FSCACHE_H
13#define _NFS_FSCACHE_H
14
15#include <linux/nfs_fs.h>
16#include <linux/nfs_mount.h>
17#include <linux/nfs4_mount.h>
18#include <linux/fscache.h>
19
20#ifdef CONFIG_NFS_FSCACHE
21
22/*
23 * set of NFS FS-Cache objects that form a superblock key
24 */
25struct nfs_fscache_key {
26 struct rb_node node;
27 struct nfs_client *nfs_client; /* the server */
28
29 /* the elements of the unique key - as used by nfs_compare_super() and
30 * nfs_compare_mount_options() to distinguish superblocks */
31 struct {
32 struct {
33 unsigned long s_flags; /* various flags
34 * (& NFS_MS_MASK) */
35 } super;
36
37 struct {
38 struct nfs_fsid fsid;
39 int flags;
40 unsigned int rsize; /* read size */
41 unsigned int wsize; /* write size */
42 unsigned int acregmin; /* attr cache timeouts */
43 unsigned int acregmax;
44 unsigned int acdirmin;
45 unsigned int acdirmax;
46 } nfs_server;
47
48 struct {
49 rpc_authflavor_t au_flavor;
50 } rpc_auth;
51
52 /* uniquifier - can be used if nfs_server.flags includes
53 * NFS_MOUNT_UNSHARED */
54 u8 uniq_len;
55 char uniquifier[0];
56 } key;
57};
58
59/*
60 * fscache-index.c
61 */
62extern struct fscache_netfs nfs_fscache_netfs;
63extern const struct fscache_cookie_def nfs_fscache_server_index_def;
64extern const struct fscache_cookie_def nfs_fscache_super_index_def;
65extern const struct fscache_cookie_def nfs_fscache_inode_object_def;
66
67extern int nfs_fscache_register(void);
68extern void nfs_fscache_unregister(void);
69
70/*
71 * fscache.c
72 */
73extern void nfs_fscache_get_client_cookie(struct nfs_client *);
74extern void nfs_fscache_release_client_cookie(struct nfs_client *);
75
76extern void nfs_fscache_get_super_cookie(struct super_block *,
77 const char *,
78 struct nfs_clone_mount *);
79extern void nfs_fscache_release_super_cookie(struct super_block *);
80
81extern void nfs_fscache_init_inode_cookie(struct inode *);
82extern void nfs_fscache_release_inode_cookie(struct inode *);
83extern void nfs_fscache_zap_inode_cookie(struct inode *);
84extern void nfs_fscache_set_inode_cookie(struct inode *, struct file *);
85extern void nfs_fscache_reset_inode_cookie(struct inode *);
86
87extern void __nfs_fscache_invalidate_page(struct page *, struct inode *);
88extern int nfs_fscache_release_page(struct page *, gfp_t);
89
90extern int __nfs_readpage_from_fscache(struct nfs_open_context *,
91 struct inode *, struct page *);
92extern int __nfs_readpages_from_fscache(struct nfs_open_context *,
93 struct inode *, struct address_space *,
94 struct list_head *, unsigned *);
95extern void __nfs_readpage_to_fscache(struct inode *, struct page *, int);
96
97/*
98 * wait for a page to complete writing to the cache
99 */
100static inline void nfs_fscache_wait_on_page_write(struct nfs_inode *nfsi,
101 struct page *page)
102{
103 if (PageFsCache(page))
104 fscache_wait_on_page_write(nfsi->fscache, page);
105}
106
107/*
108 * release the caching state associated with a page if undergoing complete page
109 * invalidation
110 */
111static inline void nfs_fscache_invalidate_page(struct page *page,
112 struct inode *inode)
113{
114 if (PageFsCache(page))
115 __nfs_fscache_invalidate_page(page, inode);
116}
117
118/*
119 * Retrieve a page from an inode data storage object.
120 */
121static inline int nfs_readpage_from_fscache(struct nfs_open_context *ctx,
122 struct inode *inode,
123 struct page *page)
124{
125 if (NFS_I(inode)->fscache)
126 return __nfs_readpage_from_fscache(ctx, inode, page);
127 return -ENOBUFS;
128}
129
130/*
131 * Retrieve a set of pages from an inode data storage object.
132 */
133static inline int nfs_readpages_from_fscache(struct nfs_open_context *ctx,
134 struct inode *inode,
135 struct address_space *mapping,
136 struct list_head *pages,
137 unsigned *nr_pages)
138{
139 if (NFS_I(inode)->fscache)
140 return __nfs_readpages_from_fscache(ctx, inode, mapping, pages,
141 nr_pages);
142 return -ENOBUFS;
143}
144
145/*
146 * Store a page newly fetched from the server in an inode data storage object
147 * in the cache.
148 */
149static inline void nfs_readpage_to_fscache(struct inode *inode,
150 struct page *page,
151 int sync)
152{
153 if (PageFsCache(page))
154 __nfs_readpage_to_fscache(inode, page, sync);
155}
156
157/*
158 * indicate the client caching state as readable text
159 */
160static inline const char *nfs_server_fscache_state(struct nfs_server *server)
161{
162 if (server->fscache && (server->options & NFS_OPTION_FSCACHE))
163 return "yes";
164 return "no ";
165}
166
167
168#else /* CONFIG_NFS_FSCACHE */
169static inline int nfs_fscache_register(void) { return 0; }
170static inline void nfs_fscache_unregister(void) {}
171
172static inline void nfs_fscache_get_client_cookie(struct nfs_client *clp) {}
173static inline void nfs_fscache_release_client_cookie(struct nfs_client *clp) {}
174
175static inline void nfs_fscache_get_super_cookie(
176 struct super_block *sb,
177 const char *uniq,
178 struct nfs_clone_mount *mntdata)
179{
180}
181static inline void nfs_fscache_release_super_cookie(struct super_block *sb) {}
182
183static inline void nfs_fscache_init_inode_cookie(struct inode *inode) {}
184static inline void nfs_fscache_release_inode_cookie(struct inode *inode) {}
185static inline void nfs_fscache_zap_inode_cookie(struct inode *inode) {}
186static inline void nfs_fscache_set_inode_cookie(struct inode *inode,
187 struct file *filp) {}
188static inline void nfs_fscache_reset_inode_cookie(struct inode *inode) {}
189
190static inline int nfs_fscache_release_page(struct page *page, gfp_t gfp)
191{
192 return 1; /* True: may release page */
193}
194static inline void nfs_fscache_invalidate_page(struct page *page,
195 struct inode *inode) {}
196static inline void nfs_fscache_wait_on_page_write(struct nfs_inode *nfsi,
197 struct page *page) {}
198
199static inline int nfs_readpage_from_fscache(struct nfs_open_context *ctx,
200 struct inode *inode,
201 struct page *page)
202{
203 return -ENOBUFS;
204}
205static inline int nfs_readpages_from_fscache(struct nfs_open_context *ctx,
206 struct inode *inode,
207 struct address_space *mapping,
208 struct list_head *pages,
209 unsigned *nr_pages)
210{
211 return -ENOBUFS;
212}
213static inline void nfs_readpage_to_fscache(struct inode *inode,
214 struct page *page, int sync) {}
215
216static inline const char *nfs_server_fscache_state(struct nfs_server *server)
217{
218 return "no ";
219}
220
221#endif /* CONFIG_NFS_FSCACHE */
222#endif /* _NFS_FSCACHE_H */
1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/* NFS filesystem cache interface definitions
3 *
4 * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
6 */
7
8#ifndef _NFS_FSCACHE_H
9#define _NFS_FSCACHE_H
10
11#include <linux/swap.h>
12#include <linux/nfs_fs.h>
13#include <linux/nfs_mount.h>
14#include <linux/nfs4_mount.h>
15#include <linux/fscache.h>
16#include <linux/iversion.h>
17
18#ifdef CONFIG_NFS_FSCACHE
19
20/*
21 * Definition of the auxiliary data attached to NFS inode storage objects
22 * within the cache.
23 *
24 * The contents of this struct are recorded in the on-disk local cache in the
25 * auxiliary data attached to the data storage object backing an inode. This
26 * permits coherency to be managed when a new inode binds to an already extant
27 * cache object.
28 */
29struct nfs_fscache_inode_auxdata {
30 s64 mtime_sec;
31 s64 mtime_nsec;
32 s64 ctime_sec;
33 s64 ctime_nsec;
34 u64 change_attr;
35};
36
37struct nfs_netfs_io_data {
38 /*
39 * NFS may split a netfs_io_subrequest into multiple RPCs, each
40 * with their own read completion. In netfs, we can only call
41 * netfs_subreq_terminated() once for each subrequest. Use the
42 * refcount here to double as a marker of the last RPC completion,
43 * and only call netfs via netfs_subreq_terminated() once.
44 */
45 refcount_t refcount;
46 struct netfs_io_subrequest *sreq;
47
48 /*
49 * Final disposition of the netfs_io_subrequest, sent in
50 * netfs_subreq_terminated()
51 */
52 atomic64_t transferred;
53 int error;
54};
55
56static inline void nfs_netfs_get(struct nfs_netfs_io_data *netfs)
57{
58 refcount_inc(&netfs->refcount);
59}
60
61static inline void nfs_netfs_put(struct nfs_netfs_io_data *netfs)
62{
63 ssize_t final_len;
64
65 /* Only the last RPC completion should call netfs_subreq_terminated() */
66 if (!refcount_dec_and_test(&netfs->refcount))
67 return;
68
69 /*
70 * The NFS pageio interface may read a complete page, even when netfs
71 * only asked for a partial page. Specifically, this may be seen when
72 * one thread is truncating a file while another one is reading the last
73 * page of the file.
74 * Correct the final length here to be no larger than the netfs subrequest
75 * length, and thus avoid netfs's "Subreq overread" warning message.
76 */
77 final_len = min_t(s64, netfs->sreq->len, atomic64_read(&netfs->transferred));
78 netfs_subreq_terminated(netfs->sreq, netfs->error ?: final_len, false);
79 kfree(netfs);
80}
81static inline void nfs_netfs_inode_init(struct nfs_inode *nfsi)
82{
83 netfs_inode_init(&nfsi->netfs, &nfs_netfs_ops, false);
84}
85extern void nfs_netfs_initiate_read(struct nfs_pgio_header *hdr);
86extern void nfs_netfs_read_completion(struct nfs_pgio_header *hdr);
87extern int nfs_netfs_folio_unlock(struct folio *folio);
88
89/*
90 * fscache.c
91 */
92extern int nfs_fscache_get_super_cookie(struct super_block *, const char *, int);
93extern void nfs_fscache_release_super_cookie(struct super_block *);
94
95extern void nfs_fscache_init_inode(struct inode *);
96extern void nfs_fscache_clear_inode(struct inode *);
97extern void nfs_fscache_open_file(struct inode *, struct file *);
98extern void nfs_fscache_release_file(struct inode *, struct file *);
99extern int nfs_netfs_readahead(struct readahead_control *ractl);
100extern int nfs_netfs_read_folio(struct file *file, struct folio *folio);
101
102static inline bool nfs_fscache_release_folio(struct folio *folio, gfp_t gfp)
103{
104 if (folio_test_fscache(folio)) {
105 if (current_is_kswapd() || !(gfp & __GFP_FS))
106 return false;
107 folio_wait_fscache(folio);
108 }
109 fscache_note_page_release(netfs_i_cookie(netfs_inode(folio->mapping->host)));
110 return true;
111}
112
113static inline void nfs_fscache_update_auxdata(struct nfs_fscache_inode_auxdata *auxdata,
114 struct inode *inode)
115{
116 memset(auxdata, 0, sizeof(*auxdata));
117 auxdata->mtime_sec = inode_get_mtime(inode).tv_sec;
118 auxdata->mtime_nsec = inode_get_mtime(inode).tv_nsec;
119 auxdata->ctime_sec = inode_get_ctime(inode).tv_sec;
120 auxdata->ctime_nsec = inode_get_ctime(inode).tv_nsec;
121
122 if (NFS_SERVER(inode)->nfs_client->rpc_ops->version == 4)
123 auxdata->change_attr = inode_peek_iversion_raw(inode);
124}
125
126/*
127 * Invalidate the contents of fscache for this inode. This will not sleep.
128 */
129static inline void nfs_fscache_invalidate(struct inode *inode, int flags)
130{
131 struct nfs_fscache_inode_auxdata auxdata;
132 struct fscache_cookie *cookie = netfs_i_cookie(&NFS_I(inode)->netfs);
133
134 nfs_fscache_update_auxdata(&auxdata, inode);
135 fscache_invalidate(cookie, &auxdata, i_size_read(inode), flags);
136}
137
138/*
139 * indicate the client caching state as readable text
140 */
141static inline const char *nfs_server_fscache_state(struct nfs_server *server)
142{
143 if (server->fscache)
144 return "yes";
145 return "no ";
146}
147
148static inline void nfs_netfs_set_pgio_header(struct nfs_pgio_header *hdr,
149 struct nfs_pageio_descriptor *desc)
150{
151 hdr->netfs = desc->pg_netfs;
152}
153static inline void nfs_netfs_set_pageio_descriptor(struct nfs_pageio_descriptor *desc,
154 struct nfs_pgio_header *hdr)
155{
156 desc->pg_netfs = hdr->netfs;
157}
158static inline void nfs_netfs_reset_pageio_descriptor(struct nfs_pageio_descriptor *desc)
159{
160 desc->pg_netfs = NULL;
161}
162#else /* CONFIG_NFS_FSCACHE */
163static inline void nfs_netfs_inode_init(struct nfs_inode *nfsi) {}
164static inline void nfs_netfs_initiate_read(struct nfs_pgio_header *hdr) {}
165static inline void nfs_netfs_read_completion(struct nfs_pgio_header *hdr) {}
166static inline int nfs_netfs_folio_unlock(struct folio *folio)
167{
168 return 1;
169}
170static inline void nfs_fscache_release_super_cookie(struct super_block *sb) {}
171
172static inline void nfs_fscache_init_inode(struct inode *inode) {}
173static inline void nfs_fscache_clear_inode(struct inode *inode) {}
174static inline void nfs_fscache_open_file(struct inode *inode,
175 struct file *filp) {}
176static inline void nfs_fscache_release_file(struct inode *inode, struct file *file) {}
177static inline int nfs_netfs_readahead(struct readahead_control *ractl)
178{
179 return -ENOBUFS;
180}
181static inline int nfs_netfs_read_folio(struct file *file, struct folio *folio)
182{
183 return -ENOBUFS;
184}
185
186static inline bool nfs_fscache_release_folio(struct folio *folio, gfp_t gfp)
187{
188 return true; /* may release folio */
189}
190static inline void nfs_fscache_invalidate(struct inode *inode, int flags) {}
191
192static inline const char *nfs_server_fscache_state(struct nfs_server *server)
193{
194 return "no ";
195}
196static inline void nfs_netfs_set_pgio_header(struct nfs_pgio_header *hdr,
197 struct nfs_pageio_descriptor *desc) {}
198static inline void nfs_netfs_set_pageio_descriptor(struct nfs_pageio_descriptor *desc,
199 struct nfs_pgio_header *hdr) {}
200static inline void nfs_netfs_reset_pageio_descriptor(struct nfs_pageio_descriptor *desc) {}
201#endif /* CONFIG_NFS_FSCACHE */
202#endif /* _NFS_FSCACHE_H */