fs/nfs/fscache.h - linux-mtk - Git at Google

 /* 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 */
	/* 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 */