[net-next-2.6.git] / fs / 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;
};

/*
 * 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 *,
					 struct nfs_clone_mount *);
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,
	const char *uniq,
	struct nfs_clone_mount *mntdata)
{
}
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 */
Commit	Line	Data
8ec442ae DH	1	/* NFS filesystem cache interface definitions
	2	*
	3	* Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
	4	* Written by David Howells (dhowells@redhat.com)
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public Licence
	8	* as published by the Free Software Foundation; either version
	9	* 2 of the Licence, or (at your option) any later version.
	10	*/
	11
	12	#ifndef _NFS_FSCACHE_H
	13	#define _NFS_FSCACHE_H
	14
	15	#include <linux/nfs_fs.h>
	16	#include <linux/nfs_mount.h>
	17	#include <linux/nfs4_mount.h>
	18	#include <linux/fscache.h>
	19
	20	#ifdef CONFIG_NFS_FSCACHE
	21
08734048 DH	22	/*
	23	* set of NFS FS-Cache objects that form a superblock key
	24	*/
	25	struct nfs_fscache_key {
	26	struct rb_node node;
	27	struct nfs_client nfs_client; / the server */
	28
	29	/* the elements of the unique key - as used by nfs_compare_super() and
	30	* nfs_compare_mount_options() to distinguish superblocks */
	31	struct {
	32	struct {
	33	unsigned long s_flags; /* various flags
	34	* (& NFS_MS_MASK) */
	35	} super;
	36
	37	struct {
	38	struct nfs_fsid fsid;
	39	int flags;
	40	unsigned int rsize; /* read size */
	41	unsigned int wsize; /* write size */
	42	unsigned int acregmin; /* attr cache timeouts */
	43	unsigned int acregmax;
	44	unsigned int acdirmin;
	45	unsigned int acdirmax;
	46	} nfs_server;
	47
	48	struct {
	49	rpc_authflavor_t au_flavor;
	50	} rpc_auth;
	51
	52	/* uniquifier - can be used if nfs_server.flags includes
	53	* NFS_MOUNT_UNSHARED */
	54	u8 uniq_len;
	55	char uniquifier[0];
	56	} key;
	57	};
	58
8ec442ae DH	59	/*
	60	* fscache-index.c
	61	*/
	62	extern struct fscache_netfs nfs_fscache_netfs;
14727281	63	extern const struct fscache_cookie_def nfs_fscache_server_index_def;
08734048	64	extern const struct fscache_cookie_def nfs_fscache_super_index_def;
10329a5d	65	extern const struct fscache_cookie_def nfs_fscache_inode_object_def;
8ec442ae DH	66
	67	extern int nfs_fscache_register(void);
	68	extern void nfs_fscache_unregister(void);
	69
14727281 DH	70	/*
	71	* fscache.c
	72	*/
	73	extern void nfs_fscache_get_client_cookie(struct nfs_client *);
	74	extern void nfs_fscache_release_client_cookie(struct nfs_client *);
	75
08734048	76	extern void nfs_fscache_get_super_cookie(struct super_block *,
2df54806 DH	77	const char *,
2df54806 DH	78	struct nfs_clone_mount *);
08734048 DH	79	extern void nfs_fscache_release_super_cookie(struct super_block *);
08734048 DH	80
ef79c097 DH	81	extern void nfs_fscache_init_inode_cookie(struct inode *);
	82	extern void nfs_fscache_release_inode_cookie(struct inode *);
	83	extern void nfs_fscache_zap_inode_cookie(struct inode *);
	84	extern void nfs_fscache_set_inode_cookie(struct inode , struct file );
	85	extern void nfs_fscache_reset_inode_cookie(struct inode *);
	86
545db45f DH	87	extern void __nfs_fscache_invalidate_page(struct page , struct inode );
	88	extern int nfs_fscache_release_page(struct page *, gfp_t);
	89
9a9fc1c0 DH	90	extern int __nfs_readpage_from_fscache(struct nfs_open_context *,
	91	struct inode , struct page );
	92	extern int __nfs_readpages_from_fscache(struct nfs_open_context *,
	93	struct inode , struct address_space ,
	94	struct list_head , unsigned );
7f8e05f6	95	extern void __nfs_readpage_to_fscache(struct inode , struct page , int);
9a9fc1c0	96
545db45f DH	97	/*
	98	* wait for a page to complete writing to the cache
	99	*/
	100	static inline void nfs_fscache_wait_on_page_write(struct nfs_inode *nfsi,
	101	struct page *page)
	102	{
	103	if (PageFsCache(page))
	104	fscache_wait_on_page_write(nfsi->fscache, page);
	105	}
	106
	107	/*
	108	* release the caching state associated with a page if undergoing complete page
	109	* invalidation
	110	*/
	111	static inline void nfs_fscache_invalidate_page(struct page *page,
	112	struct inode *inode)
	113	{
	114	if (PageFsCache(page))
	115	__nfs_fscache_invalidate_page(page, inode);
	116	}
	117
9a9fc1c0 DH	118	/*
	119	* Retrieve a page from an inode data storage object.
	120	*/
	121	static inline int nfs_readpage_from_fscache(struct nfs_open_context *ctx,
	122	struct inode *inode,
	123	struct page *page)
	124	{
	125	if (NFS_I(inode)->fscache)
	126	return __nfs_readpage_from_fscache(ctx, inode, page);
	127	return -ENOBUFS;
	128	}
	129
	130	/*
	131	* Retrieve a set of pages from an inode data storage object.
	132	*/
	133	static inline int nfs_readpages_from_fscache(struct nfs_open_context *ctx,
	134	struct inode *inode,
	135	struct address_space *mapping,
	136	struct list_head *pages,
	137	unsigned *nr_pages)
	138	{
	139	if (NFS_I(inode)->fscache)
	140	return __nfs_readpages_from_fscache(ctx, inode, mapping, pages,
	141	nr_pages);
	142	return -ENOBUFS;
	143	}
545db45f	144
7f8e05f6 DH	145	/*
	146	* Store a page newly fetched from the server in an inode data storage object
	147	* in the cache.
	148	*/
	149	static inline void nfs_readpage_to_fscache(struct inode *inode,
	150	struct page *page,
	151	int sync)
	152	{
	153	if (PageFsCache(page))
	154	__nfs_readpage_to_fscache(inode, page, sync);
	155	}
	156
5d1acff1 DH	157	/*
	158	* indicate the client caching state as readable text
	159	*/
	160	static inline const char nfs_server_fscache_state(struct nfs_server server)
	161	{
	162	if (server->fscache && (server->options & NFS_OPTION_FSCACHE))
	163	return "yes";
	164	return "no ";
	165	}
	166
7f8e05f6	167
8ec442ae DH	168	#else /* CONFIG_NFS_FSCACHE */
	169	static inline int nfs_fscache_register(void) { return 0; }
	170	static inline void nfs_fscache_unregister(void) {}
	171
14727281 DH	172	static inline void nfs_fscache_get_client_cookie(struct nfs_client *clp) {}
	173	static inline void nfs_fscache_release_client_cookie(struct nfs_client *clp) {}
	174
08734048 DH	175	static inline void nfs_fscache_get_super_cookie(
08734048 DH	176	struct super_block *sb,
2df54806 DH	177	const char *uniq,
2df54806 DH	178	struct nfs_clone_mount *mntdata)
08734048 DH	179	{
	180	}
	181	static inline void nfs_fscache_release_super_cookie(struct super_block *sb) {}
	182
ef79c097 DH	183	static inline void nfs_fscache_init_inode_cookie(struct inode *inode) {}
	184	static inline void nfs_fscache_release_inode_cookie(struct inode *inode) {}
	185	static inline void nfs_fscache_zap_inode_cookie(struct inode *inode) {}
	186	static inline void nfs_fscache_set_inode_cookie(struct inode *inode,
	187	struct file *filp) {}
	188	static inline void nfs_fscache_reset_inode_cookie(struct inode *inode) {}
	189
545db45f DH	190	static inline int nfs_fscache_release_page(struct page *page, gfp_t gfp)
	191	{
	192	return 1; /* True: may release page */
	193	}
	194	static inline void nfs_fscache_invalidate_page(struct page *page,
	195	struct inode *inode) {}
	196	static inline void nfs_fscache_wait_on_page_write(struct nfs_inode *nfsi,
	197	struct page *page) {}
	198
9a9fc1c0 DH	199	static inline int nfs_readpage_from_fscache(struct nfs_open_context *ctx,
	200	struct inode *inode,
	201	struct page *page)
	202	{
	203	return -ENOBUFS;
	204	}
	205	static inline int nfs_readpages_from_fscache(struct nfs_open_context *ctx,
	206	struct inode *inode,
	207	struct address_space *mapping,
	208	struct list_head *pages,
	209	unsigned *nr_pages)
	210	{
	211	return -ENOBUFS;
	212	}
7f8e05f6 DH	213	static inline void nfs_readpage_to_fscache(struct inode *inode,
7f8e05f6 DH	214	struct page *page, int sync) {}
9a9fc1c0	215
5d1acff1 DH	216	static inline const char nfs_server_fscache_state(struct nfs_server server)
	217	{
	218	return "no ";
	219	}
	220
8ec442ae DH	221	#endif /* CONFIG_NFS_FSCACHE */
8ec442ae DH	222	#endif /* _NFS_FSCACHE_H */