[linux-block.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
 */
#define PG_BUSY			0
#define PG_NEED_COMMIT		1
#define PG_NEED_RESCHED		2
#define PG_NEED_FLUSH		3

struct nfs_inode;
struct nfs_page {
	struct list_head	wb_list;	/* Defines state of page: */
	struct page		*wb_page;	/* page to read in/write out */
	struct nfs_open_context	*wb_context;	/* File state 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 list_head	pg_list;
	unsigned long		pg_bytes_written;
	size_t			pg_count;
	size_t			pg_bsize;
	unsigned int		pg_base;

	struct inode		*pg_inode;
	int			(*pg_doio)(struct inode *, struct list_head *, unsigned int, size_t, int);
	int 			pg_ioflags;
	int			pg_error;
};

#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_clear_request(struct nfs_page *req);
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,
			     int (*doio)(struct inode *, struct list_head *, unsigned int, size_t, int),
			     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  int nfs_wait_on_request(struct nfs_page *);
extern	void nfs_unlock_request(struct nfs_page *req);
extern  void nfs_clear_page_tag_locked(struct nfs_page *req);


/*
 * 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);
}

/*
 * Lock the page of an asynchronous request and take a reference
 */
static inline int
nfs_lock_request(struct nfs_page *req)
{
	if (test_and_set_bit(PG_BUSY, &req->wb_flags))
		return 0;
	kref_get(&req->wb_kref);
	return 1;
}

/**
 * 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	*/
	30	#define PG_BUSY 0
	31	#define PG_NEED_COMMIT 1
	32	#define PG_NEED_RESCHED 2
1a54533e	33	#define PG_NEED_FLUSH 3
1da177e4	34
3da28eb1	35	struct nfs_inode;
1da177e4	36	struct nfs_page {
2aefa104	37	struct list_head wb_list; /* Defines state of page: */
1da177e4 LT	38	struct page wb_page; / page to read in/write out */
	39	struct nfs_open_context wb_context; / File state context info */
	40	atomic_t wb_complete; /* i/os we're waiting for */
ca52fec1	41	pgoff_t wb_index; /* Offset >> PAGE_CACHE_SHIFT */
1da177e4 LT	42	unsigned int wb_offset, /* Offset & ~PAGE_CACHE_MASK */
	43	wb_pgbase, /* Start of page data */
	44	wb_bytes; /* Length of request */
c03b4024	45	struct kref wb_kref; /* reference count */
1da177e4 LT	46	unsigned long wb_flags;
	47	struct nfs_writeverf wb_verf; /* Commit cookie */
	48	};
	49
d8a5ad75 TM	50	struct nfs_pageio_descriptor {
d8a5ad75 TM	51	struct list_head pg_list;
bcb71bba	52	unsigned long pg_bytes_written;
d8a5ad75 TM	53	size_t pg_count;
	54	size_t pg_bsize;
	55	unsigned int pg_base;
bcb71bba TM	56
bcb71bba TM	57	struct inode *pg_inode;
8d5658c9	58	int (pg_doio)(struct inode , struct list_head *, unsigned int, size_t, int);
bcb71bba TM	59	int pg_ioflags;
bcb71bba TM	60	int pg_error;
d8a5ad75 TM	61	};
d8a5ad75 TM	62
1da177e4	63	#define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags))
1da177e4 LT	64
	65	extern struct nfs_page nfs_create_request(struct nfs_open_context ctx,
	66	struct inode *inode,
	67	struct page *page,
	68	unsigned int offset,
	69	unsigned int count);
	70	extern void nfs_clear_request(struct nfs_page *req);
	71	extern void nfs_release_request(struct nfs_page *req);
	72
	73
5c369683 TM	74	extern int nfs_scan_list(struct nfs_inode nfsi, struct list_head dst,
5c369683 TM	75	pgoff_t idx_start, unsigned int npages, int tag);
bcb71bba TM	76	extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
bcb71bba TM	77	struct inode *inode,
8d5658c9	78	int (doio)(struct inode , struct list_head *, unsigned int, size_t, int),
bcb71bba TM	79	size_t bsize,
bcb71bba TM	80	int how);
8b09bee3 TM	81	extern int nfs_pageio_add_request(struct nfs_pageio_descriptor *,
8b09bee3 TM	82	struct nfs_page *);
bcb71bba	83	extern void nfs_pageio_complete(struct nfs_pageio_descriptor *desc);
7fe7f848	84	extern void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t);
1da177e4 LT	85	extern int nfs_wait_on_request(struct nfs_page *);
1da177e4 LT	86	extern void nfs_unlock_request(struct nfs_page *req);
9fd367f0	87	extern void nfs_clear_page_tag_locked(struct nfs_page *req);
c6a556b8	88
1da177e4 LT	89
1da177e4 LT	90	/*
c03b4024	91	* Lock the page of an asynchronous request without getting a new reference
1da177e4 LT	92	*/
	93	static inline int
	94	nfs_lock_request_dontget(struct nfs_page *req)
	95	{
a911fd9a	96	return !test_and_set_bit(PG_BUSY, &req->wb_flags);
1da177e4 LT	97	}
	98
	99	/*
c03b4024	100	* Lock the page of an asynchronous request and take a reference
1da177e4 LT	101	*/
	102	static inline int
	103	nfs_lock_request(struct nfs_page *req)
	104	{
	105	if (test_and_set_bit(PG_BUSY, &req->wb_flags))
	106	return 0;
c03b4024	107	kref_get(&req->wb_kref);
1da177e4 LT	108	return 1;
	109	}
	110
3da28eb1 TM	111	/**
	112	* nfs_list_add_request - Insert a request into a list
	113	* @req: request
	114	* @head: head of list into which to insert the request.
	115	*/
	116	static inline void
	117	nfs_list_add_request(struct nfs_page req, struct list_head head)
	118	{
	119	list_add_tail(&req->wb_list, head);
3da28eb1 TM	120	}
3da28eb1 TM	121
1da177e4 LT	122
	123	/**
	124	* nfs_list_remove_request - Remove a request from its wb_list
	125	* @req: request
	126	*/
	127	static inline void
	128	nfs_list_remove_request(struct nfs_page *req)
	129	{
	130	if (list_empty(&req->wb_list))
	131	return;
1da177e4	132	list_del_init(&req->wb_list);
1da177e4 LT	133	}
1da177e4 LT	134
1da177e4 LT	135	static inline struct nfs_page *
	136	nfs_list_entry(struct list_head *head)
	137	{
	138	return list_entry(head, struct nfs_page, wb_list);
	139	}
	140
	141	static inline
	142	loff_t req_offset(struct nfs_page *req)
	143	{
	144	return (((loff_t)req->wb_index) << PAGE_CACHE_SHIFT) + req->wb_offset;
	145	}
	146
	147	#endif /* _LINUX_NFS_PAGE_H */