/* NFS filesystem cache interface definitions * * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public Licence * as published by the Free Software Foundation; either version * 2 of the Licence, or (at your option) any later version. */ #ifndef _NFS_FSCACHE_H #define _NFS_FSCACHE_H #include <linux/nfs_fs.h> #include <linux/nfs_mount.h> #include <linux/nfs4_mount.h> #include <linux/fscache.h> #ifdef CONFIG_NFS_FSCACHE /* * set of NFS FS-Cache objects that form a superblock key */ struct nfs_fscache_key { struct rb_node node; struct nfs_client *nfs_client; /* the server */ /* the elements of the unique key - as used by nfs_compare_super() and * nfs_compare_mount_options() to distinguish superblocks */ struct { struct { unsigned long s_flags; /* various flags * (& NFS_MS_MASK) */ } super; struct { struct nfs_fsid fsid; int flags; unsigned int rsize; /* read size */ unsigned int wsize; /* write size */ unsigned int acregmin; /* attr cache timeouts */ unsigned int acregmax; unsigned int acdirmin; unsigned int acdirmax; } nfs_server; struct { rpc_authflavor_t au_flavor; } rpc_auth; /* uniquifier - can be used if nfs_server.flags includes * NFS_MOUNT_UNSHARED */ u8 uniq_len; char uniquifier[0]; } key; }; /* * fscache-index.c */ extern struct fscache_netfs nfs_fscache_netfs; extern const struct fscache_cookie_def nfs_fscache_server_index_def; extern const struct fscache_cookie_def nfs_fscache_super_index_def; extern const struct fscache_cookie_def nfs_fscache_inode_object_def; extern int nfs_fscache_register(void); extern void nfs_fscache_unregister(void); /* * fscache.c */ extern void nfs_fscache_get_client_cookie(struct nfs_client *); extern void nfs_fscache_release_client_cookie(struct nfs_client *); extern void nfs_fscache_get_super_cookie(struct super_block *, struct nfs_parsed_mount_data *); extern void nfs_fscache_release_super_cookie(struct super_block *); extern void nfs_fscache_init_inode_cookie(struct inode *); extern void nfs_fscache_release_inode_cookie(struct inode *); extern void nfs_fscache_zap_inode_cookie(struct inode *); extern void nfs_fscache_set_inode_cookie(struct inode *, struct file *); extern void nfs_fscache_reset_inode_cookie(struct inode *); extern void __nfs_fscache_invalidate_page(struct page *, struct inode *); extern int nfs_fscache_release_page(struct page *, gfp_t); extern int __nfs_readpage_from_fscache(struct nfs_open_context *, struct inode *, struct page *); extern int __nfs_readpages_from_fscache(struct nfs_open_context *, struct inode *, struct address_space *, struct list_head *, unsigned *); extern void __nfs_readpage_to_fscache(struct inode *, struct page *, int); /* * wait for a page to complete writing to the cache */ static inline void nfs_fscache_wait_on_page_write(struct nfs_inode *nfsi, struct page *page) { if (PageFsCache(page)) fscache_wait_on_page_write(nfsi->fscache, page); } /* * release the caching state associated with a page if undergoing complete page * invalidation */ static inline void nfs_fscache_invalidate_page(struct page *page, struct inode *inode) { if (PageFsCache(page)) __nfs_fscache_invalidate_page(page, inode); } /* * Retrieve a page from an inode data storage object. */ static inline int nfs_readpage_from_fscache(struct nfs_open_context *ctx, struct inode *inode, struct page *page) { if (NFS_I(inode)->fscache) return __nfs_readpage_from_fscache(ctx, inode, page); return -ENOBUFS; } /* * Retrieve a set of pages from an inode data storage object. */ static inline int nfs_readpages_from_fscache(struct nfs_open_context *ctx, struct inode *inode, struct address_space *mapping, struct list_head *pages, unsigned *nr_pages) { if (NFS_I(inode)->fscache) return __nfs_readpages_from_fscache(ctx, inode, mapping, pages, nr_pages); return -ENOBUFS; } /* * Store a page newly fetched from the server in an inode data storage object * in the cache. */ static inline void nfs_readpage_to_fscache(struct inode *inode, struct page *page, int sync) { if (PageFsCache(page)) __nfs_readpage_to_fscache(inode, page, sync); } /* * indicate the client caching state as readable text */ static inline const char *nfs_server_fscache_state(struct nfs_server *server) { if (server->fscache && (server->options & NFS_OPTION_FSCACHE)) return "yes"; return "no "; } #else /* CONFIG_NFS_FSCACHE */ static inline int nfs_fscache_register(void) { return 0; } static inline void nfs_fscache_unregister(void) {} static inline void nfs_fscache_get_client_cookie(struct nfs_client *clp) {} static inline void nfs_fscache_release_client_cookie(struct nfs_client *clp) {} static inline void nfs_fscache_get_super_cookie( struct super_block *sb, struct nfs_parsed_mount_data *data) { } static inline void nfs_fscache_release_super_cookie(struct super_block *sb) {} static inline void nfs_fscache_init_inode_cookie(struct inode *inode) {} static inline void nfs_fscache_release_inode_cookie(struct inode *inode) {} static inline void nfs_fscache_zap_inode_cookie(struct inode *inode) {} static inline void nfs_fscache_set_inode_cookie(struct inode *inode, struct file *filp) {} static inline void nfs_fscache_reset_inode_cookie(struct inode *inode) {} static inline int nfs_fscache_release_page(struct page *page, gfp_t gfp) { return 1; /* True: may release page */ } static inline void nfs_fscache_invalidate_page(struct page *page, struct inode *inode) {} static inline void nfs_fscache_wait_on_page_write(struct nfs_inode *nfsi, struct page *page) {} static inline int nfs_readpage_from_fscache(struct nfs_open_context *ctx, struct inode *inode, struct page *page) { return -ENOBUFS; } static inline int nfs_readpages_from_fscache(struct nfs_open_context *ctx, struct inode *inode, struct address_space *mapping, struct list_head *pages, unsigned *nr_pages) { return -ENOBUFS; } static inline void nfs_readpage_to_fscache(struct inode *inode, struct page *page, int sync) {} static inline const char *nfs_server_fscache_state(struct nfs_server *server) { return "no "; } #endif /* CONFIG_NFS_FSCACHE */ #endif /* _NFS_FSCACHE_H */