[linux-2.6-block.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;
};

/*
 * 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 && (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_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 */
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
402cb8dd DH	59	/*
	60	* Definition of the auxiliary data attached to NFS inode storage objects
	61	* within the cache.
	62	*
	63	* The contents of this struct are recorded in the on-disk local cache in the
	64	* auxiliary data attached to the data storage object backing an inode. This
	65	* permits coherency to be managed when a new inode binds to an already extant
	66	* cache object.
	67	*/
	68	struct nfs_fscache_inode_auxdata {
	69	struct timespec mtime;
	70	struct timespec ctime;
402cb8dd DH	71	u64 change_attr;
	72	};
	73
8ec442ae DH	74	/*
	75	* fscache-index.c
	76	*/
	77	extern struct fscache_netfs nfs_fscache_netfs;
14727281	78	extern const struct fscache_cookie_def nfs_fscache_server_index_def;
08734048	79	extern const struct fscache_cookie_def nfs_fscache_super_index_def;
10329a5d	80	extern const struct fscache_cookie_def nfs_fscache_inode_object_def;
8ec442ae DH	81
	82	extern int nfs_fscache_register(void);
	83	extern void nfs_fscache_unregister(void);
	84
14727281 DH	85	/*
	86	* fscache.c
	87	*/
	88	extern void nfs_fscache_get_client_cookie(struct nfs_client *);
	89	extern void nfs_fscache_release_client_cookie(struct nfs_client *);
	90
2311b943	91	extern void nfs_fscache_get_super_cookie(struct super_block , const char , int);
08734048 DH	92	extern void nfs_fscache_release_super_cookie(struct super_block *);
08734048 DH	93
f1fe29b4 DH	94	extern void nfs_fscache_init_inode(struct inode *);
	95	extern void nfs_fscache_clear_inode(struct inode *);
	96	extern void nfs_fscache_open_file(struct inode , struct file );
ef79c097	97
545db45f DH	98	extern void __nfs_fscache_invalidate_page(struct page , struct inode );
	99	extern int nfs_fscache_release_page(struct page *, gfp_t);
	100
9a9fc1c0 DH	101	extern int __nfs_readpage_from_fscache(struct nfs_open_context *,
	102	struct inode , struct page );
	103	extern int __nfs_readpages_from_fscache(struct nfs_open_context *,
	104	struct inode , struct address_space ,
	105	struct list_head , unsigned );
7f8e05f6	106	extern void __nfs_readpage_to_fscache(struct inode , struct page , int);
9a9fc1c0	107
545db45f DH	108	/*
	109	* wait for a page to complete writing to the cache
	110	*/
	111	static inline void nfs_fscache_wait_on_page_write(struct nfs_inode *nfsi,
	112	struct page *page)
	113	{
	114	if (PageFsCache(page))
	115	fscache_wait_on_page_write(nfsi->fscache, page);
	116	}
	117
	118	/*
	119	* release the caching state associated with a page if undergoing complete page
	120	* invalidation
	121	*/
	122	static inline void nfs_fscache_invalidate_page(struct page *page,
	123	struct inode *inode)
	124	{
	125	if (PageFsCache(page))
	126	__nfs_fscache_invalidate_page(page, inode);
	127	}
	128
9a9fc1c0 DH	129	/*
	130	* Retrieve a page from an inode data storage object.
	131	*/
	132	static inline int nfs_readpage_from_fscache(struct nfs_open_context *ctx,
	133	struct inode *inode,
	134	struct page *page)
	135	{
	136	if (NFS_I(inode)->fscache)
	137	return __nfs_readpage_from_fscache(ctx, inode, page);
	138	return -ENOBUFS;
	139	}
	140
	141	/*
	142	* Retrieve a set of pages from an inode data storage object.
	143	*/
	144	static inline int nfs_readpages_from_fscache(struct nfs_open_context *ctx,
	145	struct inode *inode,
	146	struct address_space *mapping,
	147	struct list_head *pages,
	148	unsigned *nr_pages)
	149	{
	150	if (NFS_I(inode)->fscache)
	151	return __nfs_readpages_from_fscache(ctx, inode, mapping, pages,
	152	nr_pages);
	153	return -ENOBUFS;
	154	}
545db45f	155
7f8e05f6 DH	156	/*
	157	* Store a page newly fetched from the server in an inode data storage object
	158	* in the cache.
	159	*/
	160	static inline void nfs_readpage_to_fscache(struct inode *inode,
	161	struct page *page,
	162	int sync)
	163	{
	164	if (PageFsCache(page))
	165	__nfs_readpage_to_fscache(inode, page, sync);
	166	}
	167
de242c0b DH	168	/*
	169	* Invalidate the contents of fscache for this inode. This will not sleep.
	170	*/
	171	static inline void nfs_fscache_invalidate(struct inode *inode)
	172	{
	173	fscache_invalidate(NFS_I(inode)->fscache);
	174	}
	175
	176	/*
	177	* Wait for an object to finish being invalidated.
	178	*/
	179	static inline void nfs_fscache_wait_on_invalidate(struct inode *inode)
	180	{
	181	fscache_wait_on_invalidate(NFS_I(inode)->fscache);
	182	}
	183
5d1acff1 DH	184	/*
	185	* indicate the client caching state as readable text
	186	*/
	187	static inline const char nfs_server_fscache_state(struct nfs_server server)
	188	{
	189	if (server->fscache && (server->options & NFS_OPTION_FSCACHE))
	190	return "yes";
	191	return "no ";
	192	}
	193
8ec442ae DH	194	#else /* CONFIG_NFS_FSCACHE */
	195	static inline int nfs_fscache_register(void) { return 0; }
	196	static inline void nfs_fscache_unregister(void) {}
	197
14727281 DH	198	static inline void nfs_fscache_get_client_cookie(struct nfs_client *clp) {}
	199	static inline void nfs_fscache_release_client_cookie(struct nfs_client *clp) {}
	200
08734048 DH	201	static inline void nfs_fscache_release_super_cookie(struct super_block *sb) {}
08734048 DH	202
f1fe29b4 DH	203	static inline void nfs_fscache_init_inode(struct inode *inode) {}
	204	static inline void nfs_fscache_clear_inode(struct inode *inode) {}
	205	static inline void nfs_fscache_open_file(struct inode *inode,
	206	struct file *filp) {}
ef79c097	207
545db45f DH	208	static inline int nfs_fscache_release_page(struct page *page, gfp_t gfp)
	209	{
	210	return 1; /* True: may release page */
	211	}
	212	static inline void nfs_fscache_invalidate_page(struct page *page,
	213	struct inode *inode) {}
	214	static inline void nfs_fscache_wait_on_page_write(struct nfs_inode *nfsi,
	215	struct page *page) {}
	216
9a9fc1c0 DH	217	static inline int nfs_readpage_from_fscache(struct nfs_open_context *ctx,
	218	struct inode *inode,
	219	struct page *page)
	220	{
	221	return -ENOBUFS;
	222	}
	223	static inline int nfs_readpages_from_fscache(struct nfs_open_context *ctx,
	224	struct inode *inode,
	225	struct address_space *mapping,
	226	struct list_head *pages,
	227	unsigned *nr_pages)
	228	{
	229	return -ENOBUFS;
	230	}
7f8e05f6 DH	231	static inline void nfs_readpage_to_fscache(struct inode *inode,
7f8e05f6 DH	232	struct page *page, int sync) {}
9a9fc1c0	233
de242c0b DH	234
de242c0b DH	235	static inline void nfs_fscache_invalidate(struct inode *inode) {}
c129c293	236	static inline void nfs_fscache_wait_on_invalidate(struct inode *inode) {}
de242c0b	237
5d1acff1 DH	238	static inline const char nfs_server_fscache_state(struct nfs_server server)
	239	{
	240	return "no ";
	241	}
	242
8ec442ae DH	243	#endif /* CONFIG_NFS_FSCACHE */
8ec442ae DH	244	#endif /* _NFS_FSCACHE_H */