diff options
Diffstat (limited to 'fs/nfs/fscache.h')
| -rw-r--r-- | fs/nfs/fscache.h | 246 |
1 files changed, 246 insertions, 0 deletions
diff --git a/fs/nfs/fscache.h b/fs/nfs/fscache.h new file mode 100644 index 000000000..89d2f9566 --- /dev/null +++ b/fs/nfs/fscache.h @@ -0,0 +1,246 @@ +/* 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 { + s64 mtime_sec; + s64 mtime_nsec; + s64 ctime_sec; + s64 ctime_nsec; + 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 */ |