[deliverable/linux.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 *,
					 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 *);

/*
 * 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;
}

#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;
}

#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 DH	76	extern void nfs_fscache_get_super_cookie(struct super_block *,
	77	struct nfs_parsed_mount_data *);
	78	extern void nfs_fscache_release_super_cookie(struct super_block *);
	79
ef79c097 DH	80	extern void nfs_fscache_init_inode_cookie(struct inode *);
	81	extern void nfs_fscache_release_inode_cookie(struct inode *);
	82	extern void nfs_fscache_zap_inode_cookie(struct inode *);
	83	extern void nfs_fscache_set_inode_cookie(struct inode , struct file );
	84	extern void nfs_fscache_reset_inode_cookie(struct inode *);
	85
545db45f DH	86	extern void __nfs_fscache_invalidate_page(struct page , struct inode );
	87	extern int nfs_fscache_release_page(struct page *, gfp_t);
	88
9a9fc1c0 DH	89	extern int __nfs_readpage_from_fscache(struct nfs_open_context *,
	90	struct inode , struct page );
	91	extern int __nfs_readpages_from_fscache(struct nfs_open_context *,
	92	struct inode , struct address_space ,
	93	struct list_head , unsigned );
	94
545db45f DH	95	/*
	96	* wait for a page to complete writing to the cache
	97	*/
	98	static inline void nfs_fscache_wait_on_page_write(struct nfs_inode *nfsi,
	99	struct page *page)
	100	{
	101	if (PageFsCache(page))
	102	fscache_wait_on_page_write(nfsi->fscache, page);
	103	}
	104
	105	/*
	106	* release the caching state associated with a page if undergoing complete page
	107	* invalidation
	108	*/
	109	static inline void nfs_fscache_invalidate_page(struct page *page,
	110	struct inode *inode)
	111	{
	112	if (PageFsCache(page))
	113	__nfs_fscache_invalidate_page(page, inode);
	114	}
	115
9a9fc1c0 DH	116	/*
	117	* Retrieve a page from an inode data storage object.
	118	*/
	119	static inline int nfs_readpage_from_fscache(struct nfs_open_context *ctx,
	120	struct inode *inode,
	121	struct page *page)
	122	{
	123	if (NFS_I(inode)->fscache)
	124	return __nfs_readpage_from_fscache(ctx, inode, page);
	125	return -ENOBUFS;
	126	}
	127
	128	/*
	129	* Retrieve a set of pages from an inode data storage object.
	130	*/
	131	static inline int nfs_readpages_from_fscache(struct nfs_open_context *ctx,
	132	struct inode *inode,
	133	struct address_space *mapping,
	134	struct list_head *pages,
	135	unsigned *nr_pages)
	136	{
	137	if (NFS_I(inode)->fscache)
	138	return __nfs_readpages_from_fscache(ctx, inode, mapping, pages,
	139	nr_pages);
	140	return -ENOBUFS;
	141	}
545db45f	142
8ec442ae DH	143	#else /* CONFIG_NFS_FSCACHE */
	144	static inline int nfs_fscache_register(void) { return 0; }
	145	static inline void nfs_fscache_unregister(void) {}
	146
14727281 DH	147	static inline void nfs_fscache_get_client_cookie(struct nfs_client *clp) {}
	148	static inline void nfs_fscache_release_client_cookie(struct nfs_client *clp) {}
	149
08734048 DH	150	static inline void nfs_fscache_get_super_cookie(
	151	struct super_block *sb,
	152	struct nfs_parsed_mount_data *data)
	153	{
	154	}
	155	static inline void nfs_fscache_release_super_cookie(struct super_block *sb) {}
	156
ef79c097 DH	157	static inline void nfs_fscache_init_inode_cookie(struct inode *inode) {}
	158	static inline void nfs_fscache_release_inode_cookie(struct inode *inode) {}
	159	static inline void nfs_fscache_zap_inode_cookie(struct inode *inode) {}
	160	static inline void nfs_fscache_set_inode_cookie(struct inode *inode,
	161	struct file *filp) {}
	162	static inline void nfs_fscache_reset_inode_cookie(struct inode *inode) {}
	163
545db45f DH	164	static inline int nfs_fscache_release_page(struct page *page, gfp_t gfp)
	165	{
	166	return 1; /* True: may release page */
	167	}
	168	static inline void nfs_fscache_invalidate_page(struct page *page,
	169	struct inode *inode) {}
	170	static inline void nfs_fscache_wait_on_page_write(struct nfs_inode *nfsi,
	171	struct page *page) {}
	172
9a9fc1c0 DH	173	static inline int nfs_readpage_from_fscache(struct nfs_open_context *ctx,
	174	struct inode *inode,
	175	struct page *page)
	176	{
	177	return -ENOBUFS;
	178	}
	179	static inline int nfs_readpages_from_fscache(struct nfs_open_context *ctx,
	180	struct inode *inode,
	181	struct address_space *mapping,
	182	struct list_head *pages,
	183	unsigned *nr_pages)
	184	{
	185	return -ENOBUFS;
	186	}
	187
8ec442ae DH	188	#endif /* CONFIG_NFS_FSCACHE */
8ec442ae DH	189	#endif /* _NFS_FSCACHE_H */