[deliverable/linux.git] / include / linux / nfs_page.h

/*
 * linux/include/linux/nfs_page.h
 *
 * Copyright (C) 2000 Trond Myklebust
 *
 * NFS page cache wrapper.
 */

#ifndef _LINUX_NFS_PAGE_H
#define _LINUX_NFS_PAGE_H


#include <linux/list.h>
#include <linux/pagemap.h>
#include <linux/wait.h>
#include <linux/sunrpc/auth.h>
#include <linux/nfs_xdr.h>

#include <linux/kref.h>

/*
 * Valid flags for the radix tree
 */
#define NFS_PAGE_TAG_LOCKED	0
#define NFS_PAGE_TAG_COMMIT	1

/*
 * Valid flags for a dirty buffer
 */
enum {
	PG_BUSY = 0,
	PG_MAPPED,
	PG_CLEAN,
	PG_NEED_COMMIT,
	PG_NEED_RESCHED,
	PG_PNFS_COMMIT,
};

struct nfs_inode;
struct nfs_page {
	union {
		struct list_head	wb_list;	/* Defines state of page: */
		struct pnfs_layout_segment *wb_commit_lseg; /* Used when PG_PNFS_COMMIT set */
	};
	struct page		*wb_page;	/* page to read in/write out */
	struct nfs_open_context	*wb_context;	/* File state context info */
	struct nfs_lock_context	*wb_lock_context;	/* lock context info */
	atomic_t		wb_complete;	/* i/os we're waiting for */
	pgoff_t			wb_index;	/* Offset >> PAGE_CACHE_SHIFT */
	unsigned int		wb_offset,	/* Offset & ~PAGE_CACHE_MASK */
				wb_pgbase,	/* Start of page data */
				wb_bytes;	/* Length of request */
	struct kref		wb_kref;	/* reference count */
	unsigned long		wb_flags;
	struct nfs_writeverf	wb_verf;	/* Commit cookie */
};

struct nfs_pageio_descriptor;
struct nfs_pageio_ops {
	void	(*pg_init)(struct nfs_pageio_descriptor *, struct nfs_page *);
	bool	(*pg_test)(struct nfs_pageio_descriptor *, struct nfs_page *, struct nfs_page *);
	int	(*pg_doio)(struct nfs_pageio_descriptor *);
};

struct nfs_pageio_descriptor {
	struct list_head	pg_list;
	unsigned long		pg_bytes_written;
	size_t			pg_count;
	size_t			pg_bsize;
	unsigned int		pg_base;
	char			pg_moreio;

	struct inode		*pg_inode;
	const struct nfs_pageio_ops *pg_ops;
	int 			pg_ioflags;
	int			pg_error;
	const struct rpc_call_ops *pg_rpc_callops;
	struct pnfs_layout_segment *pg_lseg;
};

#define NFS_WBACK_BUSY(req)	(test_bit(PG_BUSY,&(req)->wb_flags))

extern	struct nfs_page *nfs_create_request(struct nfs_open_context *ctx,
					    struct inode *inode,
					    struct page *page,
					    unsigned int offset,
					    unsigned int count);
extern	void nfs_release_request(struct nfs_page *req);


extern	int nfs_scan_list(struct nfs_inode *nfsi, struct list_head *dst,
			  pgoff_t idx_start, unsigned int npages, int tag);
extern	void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
			     struct inode *inode,
			     const struct nfs_pageio_ops *pg_ops,
			     size_t bsize,
			     int how);
extern	int nfs_pageio_add_request(struct nfs_pageio_descriptor *,
				   struct nfs_page *);
extern	void nfs_pageio_complete(struct nfs_pageio_descriptor *desc);
extern	void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t);
extern bool nfs_generic_pg_test(struct nfs_pageio_descriptor *desc,
				struct nfs_page *prev,
				struct nfs_page *req);
extern  int nfs_wait_on_request(struct nfs_page *);
extern	void nfs_unlock_request(struct nfs_page *req);
extern	int nfs_set_page_tag_locked(struct nfs_page *req);
extern  void nfs_clear_page_tag_locked(struct nfs_page *req);

extern	int nfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc);
extern	int nfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc);


/*
 * Lock the page of an asynchronous request without getting a new reference
 */
static inline int
nfs_lock_request_dontget(struct nfs_page *req)
{
	return !test_and_set_bit(PG_BUSY, &req->wb_flags);
}

/**
 * nfs_list_add_request - Insert a request into a list
 * @req: request
 * @head: head of list into which to insert the request.
 */
static inline void
nfs_list_add_request(struct nfs_page *req, struct list_head *head)
{
	list_add_tail(&req->wb_list, head);
}


/**
 * nfs_list_remove_request - Remove a request from its wb_list
 * @req: request
 */
static inline void
nfs_list_remove_request(struct nfs_page *req)
{
	if (list_empty(&req->wb_list))
		return;
	list_del_init(&req->wb_list);
}

static inline struct nfs_page *
nfs_list_entry(struct list_head *head)
{
	return list_entry(head, struct nfs_page, wb_list);
}

static inline
loff_t req_offset(struct nfs_page *req)
{
	return (((loff_t)req->wb_index) << PAGE_CACHE_SHIFT) + req->wb_offset;
}

#endif /* _LINUX_NFS_PAGE_H */
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/include/linux/nfs_page.h
	3	*
	4	* Copyright (C) 2000 Trond Myklebust
	5	*
	6	* NFS page cache wrapper.
	7	*/
	8
	9	#ifndef _LINUX_NFS_PAGE_H
	10	#define _LINUX_NFS_PAGE_H
	11
	12
	13	#include <linux/list.h>
	14	#include <linux/pagemap.h>
	15	#include <linux/wait.h>
1da177e4 LT	16	#include <linux/sunrpc/auth.h>
	17	#include <linux/nfs_xdr.h>
	18
c03b4024	19	#include <linux/kref.h>
1da177e4	20
c6a556b8 TM	21	/*
	22	* Valid flags for the radix tree
	23	*/
9fd367f0	24	#define NFS_PAGE_TAG_LOCKED 0
5c369683	25	#define NFS_PAGE_TAG_COMMIT 1
c6a556b8	26
1da177e4 LT	27	/*
	28	* Valid flags for a dirty buffer
	29	*/
e468bae9 TM	30	enum {
e468bae9 TM	31	PG_BUSY = 0,
2df485a7	32	PG_MAPPED,
e468bae9 TM	33	PG_CLEAN,
	34	PG_NEED_COMMIT,
	35	PG_NEED_RESCHED,
a861a1e1	36	PG_PNFS_COMMIT,
e468bae9	37	};
1da177e4	38
3da28eb1	39	struct nfs_inode;
1da177e4	40	struct nfs_page {
a861a1e1 FI	41	union {
	42	struct list_head wb_list; /* Defines state of page: */
	43	struct pnfs_layout_segment wb_commit_lseg; / Used when PG_PNFS_COMMIT set */
	44	};
1da177e4 LT	45	struct page wb_page; / page to read in/write out */
1da177e4 LT	46	struct nfs_open_context wb_context; / File state context info */
f11ac8db	47	struct nfs_lock_context wb_lock_context; / lock context info */
1da177e4	48	atomic_t wb_complete; /* i/os we're waiting for */
ca52fec1	49	pgoff_t wb_index; /* Offset >> PAGE_CACHE_SHIFT */
1da177e4 LT	50	unsigned int wb_offset, /* Offset & ~PAGE_CACHE_MASK */
	51	wb_pgbase, /* Start of page data */
	52	wb_bytes; /* Length of request */
c03b4024	53	struct kref wb_kref; /* reference count */
1da177e4 LT	54	unsigned long wb_flags;
	55	struct nfs_writeverf wb_verf; /* Commit cookie */
	56	};
	57
1751c363 TM	58	struct nfs_pageio_descriptor;
1751c363 TM	59	struct nfs_pageio_ops {
d8007d4d	60	void (pg_init)(struct nfs_pageio_descriptor , struct nfs_page *);
1751c363 TM	61	bool (pg_test)(struct nfs_pageio_descriptor , struct nfs_page , struct nfs_page );
	62	int (pg_doio)(struct nfs_pageio_descriptor );
	63	};
	64
d8a5ad75 TM	65	struct nfs_pageio_descriptor {
d8a5ad75 TM	66	struct list_head pg_list;
bcb71bba	67	unsigned long pg_bytes_written;
d8a5ad75 TM	68	size_t pg_count;
	69	size_t pg_bsize;
	70	unsigned int pg_base;
b31268ac	71	char pg_moreio;
bcb71bba TM	72
bcb71bba TM	73	struct inode *pg_inode;
1751c363	74	const struct nfs_pageio_ops *pg_ops;
bcb71bba TM	75	int pg_ioflags;
bcb71bba TM	76	int pg_error;
50828d7e	77	const struct rpc_call_ops *pg_rpc_callops;
94ad1c80	78	struct pnfs_layout_segment *pg_lseg;
d8a5ad75 TM	79	};
d8a5ad75 TM	80
1da177e4	81	#define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags))
1da177e4 LT	82
	83	extern struct nfs_page nfs_create_request(struct nfs_open_context ctx,
	84	struct inode *inode,
	85	struct page *page,
	86	unsigned int offset,
	87	unsigned int count);
1da177e4 LT	88	extern void nfs_release_request(struct nfs_page *req);
	89
	90
5c369683 TM	91	extern int nfs_scan_list(struct nfs_inode nfsi, struct list_head dst,
5c369683 TM	92	pgoff_t idx_start, unsigned int npages, int tag);
bcb71bba TM	93	extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
bcb71bba TM	94	struct inode *inode,
1751c363	95	const struct nfs_pageio_ops *pg_ops,
bcb71bba TM	96	size_t bsize,
bcb71bba TM	97	int how);
8b09bee3 TM	98	extern int nfs_pageio_add_request(struct nfs_pageio_descriptor *,
8b09bee3 TM	99	struct nfs_page *);
bcb71bba	100	extern void nfs_pageio_complete(struct nfs_pageio_descriptor *desc);
7fe7f848	101	extern void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t);
19345cb2 BH	102	extern bool nfs_generic_pg_test(struct nfs_pageio_descriptor *desc,
	103	struct nfs_page *prev,
	104	struct nfs_page *req);
1da177e4 LT	105	extern int nfs_wait_on_request(struct nfs_page *);
1da177e4 LT	106	extern void nfs_unlock_request(struct nfs_page *req);
acee478a	107	extern int nfs_set_page_tag_locked(struct nfs_page *req);
9fd367f0	108	extern void nfs_clear_page_tag_locked(struct nfs_page *req);
c6a556b8	109
1751c363 TM	110	extern int nfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc);
	111	extern int nfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc);
	112
1da177e4 LT	113
1da177e4 LT	114	/*
c03b4024	115	* Lock the page of an asynchronous request without getting a new reference
1da177e4 LT	116	*/
	117	static inline int
	118	nfs_lock_request_dontget(struct nfs_page *req)
	119	{
a911fd9a	120	return !test_and_set_bit(PG_BUSY, &req->wb_flags);
1da177e4 LT	121	}
1da177e4 LT	122
3da28eb1 TM	123	/**
	124	* nfs_list_add_request - Insert a request into a list
	125	* @req: request
	126	* @head: head of list into which to insert the request.
	127	*/
	128	static inline void
	129	nfs_list_add_request(struct nfs_page req, struct list_head head)
	130	{
	131	list_add_tail(&req->wb_list, head);
3da28eb1 TM	132	}
3da28eb1 TM	133
1da177e4 LT	134
	135	/**
	136	* nfs_list_remove_request - Remove a request from its wb_list
	137	* @req: request
	138	*/
	139	static inline void
	140	nfs_list_remove_request(struct nfs_page *req)
	141	{
	142	if (list_empty(&req->wb_list))
	143	return;
1da177e4	144	list_del_init(&req->wb_list);
1da177e4 LT	145	}
1da177e4 LT	146
1da177e4 LT	147	static inline struct nfs_page *
	148	nfs_list_entry(struct list_head *head)
	149	{
	150	return list_entry(head, struct nfs_page, wb_list);
	151	}
	152
	153	static inline
	154	loff_t req_offset(struct nfs_page *req)
	155	{
	156	return (((loff_t)req->wb_index) << PAGE_CACHE_SHIFT) + req->wb_offset;
	157	}
	158
	159	#endif /* _LINUX_NFS_PAGE_H */