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 */
29 struct 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
37 struct 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
nfs_netfs_get(struct nfs_netfs_io_data * netfs)56 static inline void nfs_netfs_get(struct nfs_netfs_io_data *netfs)
57 {
58 refcount_inc(&netfs->refcount);
59 }
60
nfs_netfs_put(struct nfs_netfs_io_data * netfs)61 static inline void nfs_netfs_put(struct nfs_netfs_io_data *netfs)
62 {
63 /* Only the last RPC completion should call netfs_subreq_terminated() */
64 if (!refcount_dec_and_test(&netfs->refcount))
65 return;
66
67 /*
68 * The NFS pageio interface may read a complete page, even when netfs
69 * only asked for a partial page. Specifically, this may be seen when
70 * one thread is truncating a file while another one is reading the last
71 * page of the file.
72 * Correct the final length here to be no larger than the netfs subrequest
73 * length, and thus avoid netfs's "Subreq overread" warning message.
74 */
75 netfs->sreq->transferred = min_t(s64, netfs->sreq->len,
76 atomic64_read(&netfs->transferred));
77 netfs_read_subreq_terminated(netfs->sreq, netfs->error, false);
78 kfree(netfs);
79 }
nfs_netfs_inode_init(struct nfs_inode * nfsi)80 static inline void nfs_netfs_inode_init(struct nfs_inode *nfsi)
81 {
82 netfs_inode_init(&nfsi->netfs, &nfs_netfs_ops, false);
83 }
84 extern void nfs_netfs_initiate_read(struct nfs_pgio_header *hdr);
85 extern void nfs_netfs_read_completion(struct nfs_pgio_header *hdr);
86 extern int nfs_netfs_folio_unlock(struct folio *folio);
87
88 /*
89 * fscache.c
90 */
91 extern int nfs_fscache_get_super_cookie(struct super_block *, const char *, int);
92 extern void nfs_fscache_release_super_cookie(struct super_block *);
93
94 extern void nfs_fscache_init_inode(struct inode *);
95 extern void nfs_fscache_clear_inode(struct inode *);
96 extern void nfs_fscache_open_file(struct inode *, struct file *);
97 extern void nfs_fscache_release_file(struct inode *, struct file *);
98 extern int nfs_netfs_readahead(struct readahead_control *ractl);
99 extern int nfs_netfs_read_folio(struct file *file, struct folio *folio);
100
nfs_fscache_release_folio(struct folio * folio,gfp_t gfp)101 static inline bool nfs_fscache_release_folio(struct folio *folio, gfp_t gfp)
102 {
103 if (folio_test_private_2(folio)) { /* [DEPRECATED] */
104 if (current_is_kswapd() || !(gfp & __GFP_FS))
105 return false;
106 folio_wait_private_2(folio);
107 }
108 fscache_note_page_release(netfs_i_cookie(netfs_inode(folio->mapping->host)));
109 return true;
110 }
111
nfs_fscache_update_auxdata(struct nfs_fscache_inode_auxdata * auxdata,struct inode * inode)112 static inline void nfs_fscache_update_auxdata(struct nfs_fscache_inode_auxdata *auxdata,
113 struct inode *inode)
114 {
115 memset(auxdata, 0, sizeof(*auxdata));
116 auxdata->mtime_sec = inode_get_mtime(inode).tv_sec;
117 auxdata->mtime_nsec = inode_get_mtime(inode).tv_nsec;
118 auxdata->ctime_sec = inode_get_ctime(inode).tv_sec;
119 auxdata->ctime_nsec = inode_get_ctime(inode).tv_nsec;
120
121 if (NFS_SERVER(inode)->nfs_client->rpc_ops->version == 4)
122 auxdata->change_attr = inode_peek_iversion_raw(inode);
123 }
124
125 /*
126 * Invalidate the contents of fscache for this inode. This will not sleep.
127 */
nfs_fscache_invalidate(struct inode * inode,int flags)128 static inline void nfs_fscache_invalidate(struct inode *inode, int flags)
129 {
130 struct nfs_fscache_inode_auxdata auxdata;
131 struct fscache_cookie *cookie = netfs_i_cookie(&NFS_I(inode)->netfs);
132
133 nfs_fscache_update_auxdata(&auxdata, inode);
134 fscache_invalidate(cookie, &auxdata, i_size_read(inode), flags);
135 }
136
137 /*
138 * indicate the client caching state as readable text
139 */
nfs_server_fscache_state(struct nfs_server * server)140 static inline const char *nfs_server_fscache_state(struct nfs_server *server)
141 {
142 if (server->fscache)
143 return "yes";
144 return "no ";
145 }
146
nfs_netfs_set_pgio_header(struct nfs_pgio_header * hdr,struct nfs_pageio_descriptor * desc)147 static inline void nfs_netfs_set_pgio_header(struct nfs_pgio_header *hdr,
148 struct nfs_pageio_descriptor *desc)
149 {
150 hdr->netfs = desc->pg_netfs;
151 }
nfs_netfs_set_pageio_descriptor(struct nfs_pageio_descriptor * desc,struct nfs_pgio_header * hdr)152 static inline void nfs_netfs_set_pageio_descriptor(struct nfs_pageio_descriptor *desc,
153 struct nfs_pgio_header *hdr)
154 {
155 desc->pg_netfs = hdr->netfs;
156 }
nfs_netfs_reset_pageio_descriptor(struct nfs_pageio_descriptor * desc)157 static inline void nfs_netfs_reset_pageio_descriptor(struct nfs_pageio_descriptor *desc)
158 {
159 desc->pg_netfs = NULL;
160 }
161 #else /* CONFIG_NFS_FSCACHE */
nfs_netfs_inode_init(struct nfs_inode * nfsi)162 static inline void nfs_netfs_inode_init(struct nfs_inode *nfsi) {}
nfs_netfs_initiate_read(struct nfs_pgio_header * hdr)163 static inline void nfs_netfs_initiate_read(struct nfs_pgio_header *hdr) {}
nfs_netfs_read_completion(struct nfs_pgio_header * hdr)164 static inline void nfs_netfs_read_completion(struct nfs_pgio_header *hdr) {}
nfs_netfs_folio_unlock(struct folio * folio)165 static inline int nfs_netfs_folio_unlock(struct folio *folio)
166 {
167 return 1;
168 }
nfs_fscache_release_super_cookie(struct super_block * sb)169 static inline void nfs_fscache_release_super_cookie(struct super_block *sb) {}
170
nfs_fscache_init_inode(struct inode * inode)171 static inline void nfs_fscache_init_inode(struct inode *inode) {}
nfs_fscache_clear_inode(struct inode * inode)172 static inline void nfs_fscache_clear_inode(struct inode *inode) {}
nfs_fscache_open_file(struct inode * inode,struct file * filp)173 static inline void nfs_fscache_open_file(struct inode *inode,
174 struct file *filp) {}
nfs_fscache_release_file(struct inode * inode,struct file * file)175 static inline void nfs_fscache_release_file(struct inode *inode, struct file *file) {}
nfs_netfs_readahead(struct readahead_control * ractl)176 static inline int nfs_netfs_readahead(struct readahead_control *ractl)
177 {
178 return -ENOBUFS;
179 }
nfs_netfs_read_folio(struct file * file,struct folio * folio)180 static inline int nfs_netfs_read_folio(struct file *file, struct folio *folio)
181 {
182 return -ENOBUFS;
183 }
184
nfs_fscache_release_folio(struct folio * folio,gfp_t gfp)185 static inline bool nfs_fscache_release_folio(struct folio *folio, gfp_t gfp)
186 {
187 return true; /* may release folio */
188 }
nfs_fscache_invalidate(struct inode * inode,int flags)189 static inline void nfs_fscache_invalidate(struct inode *inode, int flags) {}
190
nfs_server_fscache_state(struct nfs_server * server)191 static inline const char *nfs_server_fscache_state(struct nfs_server *server)
192 {
193 return "no ";
194 }
nfs_netfs_set_pgio_header(struct nfs_pgio_header * hdr,struct nfs_pageio_descriptor * desc)195 static inline void nfs_netfs_set_pgio_header(struct nfs_pgio_header *hdr,
196 struct nfs_pageio_descriptor *desc) {}
nfs_netfs_set_pageio_descriptor(struct nfs_pageio_descriptor * desc,struct nfs_pgio_header * hdr)197 static inline void nfs_netfs_set_pageio_descriptor(struct nfs_pageio_descriptor *desc,
198 struct nfs_pgio_header *hdr) {}
nfs_netfs_reset_pageio_descriptor(struct nfs_pageio_descriptor * desc)199 static inline void nfs_netfs_reset_pageio_descriptor(struct nfs_pageio_descriptor *desc) {}
200 #endif /* CONFIG_NFS_FSCACHE */
201 #endif /* _NFS_FSCACHE_H */
202