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 /* 38 * fscache.c 39 */ 40 extern int nfs_fscache_get_super_cookie(struct super_block *, const char *, int); 41 extern void nfs_fscache_release_super_cookie(struct super_block *); 42 43 extern void nfs_fscache_init_inode(struct inode *); 44 extern void nfs_fscache_clear_inode(struct inode *); 45 extern void nfs_fscache_open_file(struct inode *, struct file *); 46 extern void nfs_fscache_release_file(struct inode *, struct file *); 47 48 extern int __nfs_readpage_from_fscache(struct inode *, struct page *); 49 extern void __nfs_read_completion_to_fscache(struct nfs_pgio_header *hdr, 50 unsigned long bytes); 51 extern void __nfs_readpage_to_fscache(struct inode *, struct page *); 52 53 static inline int nfs_fscache_release_page(struct page *page, gfp_t gfp) 54 { 55 if (PageFsCache(page)) { 56 if (current_is_kswapd() || !(gfp & __GFP_FS)) 57 return false; 58 wait_on_page_fscache(page); 59 fscache_note_page_release(nfs_i_fscache(page->mapping->host)); 60 nfs_inc_fscache_stats(page->mapping->host, 61 NFSIOS_FSCACHE_PAGES_UNCACHED); 62 } 63 return true; 64 } 65 66 /* 67 * Retrieve a page from an inode data storage object. 68 */ 69 static inline int nfs_readpage_from_fscache(struct inode *inode, 70 struct page *page) 71 { 72 if (NFS_I(inode)->fscache) 73 return __nfs_readpage_from_fscache(inode, page); 74 return -ENOBUFS; 75 } 76 77 /* 78 * Store a page newly fetched from the server in an inode data storage object 79 * in the cache. 80 */ 81 static inline void nfs_readpage_to_fscache(struct inode *inode, 82 struct page *page) 83 { 84 if (NFS_I(inode)->fscache) 85 __nfs_readpage_to_fscache(inode, page); 86 } 87 88 static inline void nfs_fscache_update_auxdata(struct nfs_fscache_inode_auxdata *auxdata, 89 struct nfs_inode *nfsi) 90 { 91 memset(auxdata, 0, sizeof(*auxdata)); 92 auxdata->mtime_sec = nfsi->vfs_inode.i_mtime.tv_sec; 93 auxdata->mtime_nsec = nfsi->vfs_inode.i_mtime.tv_nsec; 94 auxdata->ctime_sec = nfsi->vfs_inode.i_ctime.tv_sec; 95 auxdata->ctime_nsec = nfsi->vfs_inode.i_ctime.tv_nsec; 96 97 if (NFS_SERVER(&nfsi->vfs_inode)->nfs_client->rpc_ops->version == 4) 98 auxdata->change_attr = inode_peek_iversion_raw(&nfsi->vfs_inode); 99 } 100 101 /* 102 * Invalidate the contents of fscache for this inode. This will not sleep. 103 */ 104 static inline void nfs_fscache_invalidate(struct inode *inode, int flags) 105 { 106 struct nfs_fscache_inode_auxdata auxdata; 107 struct nfs_inode *nfsi = NFS_I(inode); 108 109 if (nfsi->fscache) { 110 nfs_fscache_update_auxdata(&auxdata, nfsi); 111 fscache_invalidate(nfsi->fscache, &auxdata, 112 i_size_read(&nfsi->vfs_inode), flags); 113 } 114 } 115 116 /* 117 * indicate the client caching state as readable text 118 */ 119 static inline const char *nfs_server_fscache_state(struct nfs_server *server) 120 { 121 if (server->fscache) 122 return "yes"; 123 return "no "; 124 } 125 126 #else /* CONFIG_NFS_FSCACHE */ 127 static inline void nfs_fscache_release_super_cookie(struct super_block *sb) {} 128 129 static inline void nfs_fscache_init_inode(struct inode *inode) {} 130 static inline void nfs_fscache_clear_inode(struct inode *inode) {} 131 static inline void nfs_fscache_open_file(struct inode *inode, 132 struct file *filp) {} 133 static inline void nfs_fscache_release_file(struct inode *inode, struct file *file) {} 134 135 static inline int nfs_fscache_release_page(struct page *page, gfp_t gfp) 136 { 137 return 1; /* True: may release page */ 138 } 139 static inline int nfs_readpage_from_fscache(struct inode *inode, 140 struct page *page) 141 { 142 return -ENOBUFS; 143 } 144 static inline void nfs_readpage_to_fscache(struct inode *inode, 145 struct page *page) {} 146 147 148 static inline void nfs_fscache_invalidate(struct inode *inode, int flags) {} 149 150 static inline const char *nfs_server_fscache_state(struct nfs_server *server) 151 { 152 return "no "; 153 } 154 155 #endif /* CONFIG_NFS_FSCACHE */ 156 #endif /* _NFS_FSCACHE_H */ 157