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 56 static inline void nfs_netfs_get(struct nfs_netfs_io_data *netfs) 57 { 58 refcount_inc(&netfs->refcount); 59 } 60 61 static 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 } 81 static inline void nfs_netfs_inode_init(struct nfs_inode *nfsi) 82 { 83 netfs_inode_init(&nfsi->netfs, &nfs_netfs_ops, false); 84 /* [DEPRECATED] Use PG_private_2 to mark folio being written to the cache. */ 85 __set_bit(NETFS_ICTX_USE_PGPRIV2, &nfsi->netfs.flags); 86 } 87 extern void nfs_netfs_initiate_read(struct nfs_pgio_header *hdr); 88 extern void nfs_netfs_read_completion(struct nfs_pgio_header *hdr); 89 extern int nfs_netfs_folio_unlock(struct folio *folio); 90 91 /* 92 * fscache.c 93 */ 94 extern int nfs_fscache_get_super_cookie(struct super_block *, const char *, int); 95 extern void nfs_fscache_release_super_cookie(struct super_block *); 96 97 extern void nfs_fscache_init_inode(struct inode *); 98 extern void nfs_fscache_clear_inode(struct inode *); 99 extern void nfs_fscache_open_file(struct inode *, struct file *); 100 extern void nfs_fscache_release_file(struct inode *, struct file *); 101 extern int nfs_netfs_readahead(struct readahead_control *ractl); 102 extern int nfs_netfs_read_folio(struct file *file, struct folio *folio); 103 104 static inline bool nfs_fscache_release_folio(struct folio *folio, gfp_t gfp) 105 { 106 if (folio_test_private_2(folio)) { /* [DEPRECATED] */ 107 if (current_is_kswapd() || !(gfp & __GFP_FS)) 108 return false; 109 folio_wait_private_2(folio); 110 } 111 fscache_note_page_release(netfs_i_cookie(netfs_inode(folio->mapping->host))); 112 return true; 113 } 114 115 static inline void nfs_fscache_update_auxdata(struct nfs_fscache_inode_auxdata *auxdata, 116 struct inode *inode) 117 { 118 memset(auxdata, 0, sizeof(*auxdata)); 119 auxdata->mtime_sec = inode_get_mtime(inode).tv_sec; 120 auxdata->mtime_nsec = inode_get_mtime(inode).tv_nsec; 121 auxdata->ctime_sec = inode_get_ctime(inode).tv_sec; 122 auxdata->ctime_nsec = inode_get_ctime(inode).tv_nsec; 123 124 if (NFS_SERVER(inode)->nfs_client->rpc_ops->version == 4) 125 auxdata->change_attr = inode_peek_iversion_raw(inode); 126 } 127 128 /* 129 * Invalidate the contents of fscache for this inode. This will not sleep. 130 */ 131 static inline void nfs_fscache_invalidate(struct inode *inode, int flags) 132 { 133 struct nfs_fscache_inode_auxdata auxdata; 134 struct fscache_cookie *cookie = netfs_i_cookie(&NFS_I(inode)->netfs); 135 136 nfs_fscache_update_auxdata(&auxdata, inode); 137 fscache_invalidate(cookie, &auxdata, i_size_read(inode), flags); 138 } 139 140 /* 141 * indicate the client caching state as readable text 142 */ 143 static inline const char *nfs_server_fscache_state(struct nfs_server *server) 144 { 145 if (server->fscache) 146 return "yes"; 147 return "no "; 148 } 149 150 static inline void nfs_netfs_set_pgio_header(struct nfs_pgio_header *hdr, 151 struct nfs_pageio_descriptor *desc) 152 { 153 hdr->netfs = desc->pg_netfs; 154 } 155 static inline void nfs_netfs_set_pageio_descriptor(struct nfs_pageio_descriptor *desc, 156 struct nfs_pgio_header *hdr) 157 { 158 desc->pg_netfs = hdr->netfs; 159 } 160 static inline void nfs_netfs_reset_pageio_descriptor(struct nfs_pageio_descriptor *desc) 161 { 162 desc->pg_netfs = NULL; 163 } 164 #else /* CONFIG_NFS_FSCACHE */ 165 static inline void nfs_netfs_inode_init(struct nfs_inode *nfsi) {} 166 static inline void nfs_netfs_initiate_read(struct nfs_pgio_header *hdr) {} 167 static inline void nfs_netfs_read_completion(struct nfs_pgio_header *hdr) {} 168 static inline int nfs_netfs_folio_unlock(struct folio *folio) 169 { 170 return 1; 171 } 172 static inline void nfs_fscache_release_super_cookie(struct super_block *sb) {} 173 174 static inline void nfs_fscache_init_inode(struct inode *inode) {} 175 static inline void nfs_fscache_clear_inode(struct inode *inode) {} 176 static inline void nfs_fscache_open_file(struct inode *inode, 177 struct file *filp) {} 178 static inline void nfs_fscache_release_file(struct inode *inode, struct file *file) {} 179 static inline int nfs_netfs_readahead(struct readahead_control *ractl) 180 { 181 return -ENOBUFS; 182 } 183 static inline int nfs_netfs_read_folio(struct file *file, struct folio *folio) 184 { 185 return -ENOBUFS; 186 } 187 188 static inline bool nfs_fscache_release_folio(struct folio *folio, gfp_t gfp) 189 { 190 return true; /* may release folio */ 191 } 192 static inline void nfs_fscache_invalidate(struct inode *inode, int flags) {} 193 194 static inline const char *nfs_server_fscache_state(struct nfs_server *server) 195 { 196 return "no "; 197 } 198 static inline void nfs_netfs_set_pgio_header(struct nfs_pgio_header *hdr, 199 struct nfs_pageio_descriptor *desc) {} 200 static inline void nfs_netfs_set_pageio_descriptor(struct nfs_pageio_descriptor *desc, 201 struct nfs_pgio_header *hdr) {} 202 static inline void nfs_netfs_reset_pageio_descriptor(struct nfs_pageio_descriptor *desc) {} 203 #endif /* CONFIG_NFS_FSCACHE */ 204 #endif /* _NFS_FSCACHE_H */ 205