| /* 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; |
| }; |
| |
| /* |
| * Definition of the auxiliary data attached to NFS inode storage objects |
| * within the cache. |
| * |
| * The contents of this struct are recorded in the on-disk local cache in the |
| * auxiliary data attached to the data storage object backing an inode. This |
| * permits coherency to be managed when a new inode binds to an already extant |
| * cache object. |
| */ |
| struct nfs_fscache_inode_auxdata { |
| struct timespec mtime; |
| struct timespec ctime; |
| u64 change_attr; |
| }; |
| |
| /* |
| * 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 *, const char *, int); |
| extern void nfs_fscache_release_super_cookie(struct super_block *); |
| |
| extern void nfs_fscache_init_inode(struct inode *); |
| extern void nfs_fscache_clear_inode(struct inode *); |
| extern void nfs_fscache_open_file(struct inode *, struct file *); |
| |
| 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); |
| } |
| |
| /* |
| * Invalidate the contents of fscache for this inode. This will not sleep. |
| */ |
| static inline void nfs_fscache_invalidate(struct inode *inode) |
| { |
| fscache_invalidate(NFS_I(inode)->fscache); |
| } |
| |
| /* |
| * Wait for an object to finish being invalidated. |
| */ |
| static inline void nfs_fscache_wait_on_invalidate(struct inode *inode) |
| { |
| fscache_wait_on_invalidate(NFS_I(inode)->fscache); |
| } |
| |
| /* |
| * indicate the client caching state as readable text |
| */ |
| static inline const char *nfs_server_fscache_state(struct nfs_server *server) |
| { |
| if (server->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_release_super_cookie(struct super_block *sb) {} |
| |
| static inline void nfs_fscache_init_inode(struct inode *inode) {} |
| static inline void nfs_fscache_clear_inode(struct inode *inode) {} |
| static inline void nfs_fscache_open_file(struct inode *inode, |
| struct file *filp) {} |
| |
| 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 void nfs_fscache_invalidate(struct inode *inode) {} |
| static inline void nfs_fscache_wait_on_invalidate(struct inode *inode) {} |
| |
| static inline const char *nfs_server_fscache_state(struct nfs_server *server) |
| { |
| return "no "; |
| } |
| |
| #endif /* CONFIG_NFS_FSCACHE */ |
| #endif /* _NFS_FSCACHE_H */ |