[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 <asm/atomic.h>

/*
 * Valid flags for the radix tree
 */
#define NFS_PAGE_TAG_DIRTY	0
#define NFS_PAGE_TAG_WRITEBACK	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: */
				*wb_list_head;	/*      read/write/commit */
	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 */
	unsigned long		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 */
	atomic_t		wb_count;	/* reference count */
	unsigned long		wb_flags;
	struct nfs_writeverf	wb_verf;	/* Commit cookie */
};

#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	long nfs_scan_dirty(struct address_space *mapping,
				struct writeback_control *wbc,
				struct list_head *dst);
extern	int nfs_scan_list(struct nfs_inode *nfsi, struct list_head *head, struct list_head *dst,
			  unsigned long idx_start, unsigned int npages);
extern	int nfs_coalesce_requests(struct list_head *, struct list_head *,
				  unsigned int);
extern  int nfs_wait_on_request(struct nfs_page *);
extern	void nfs_unlock_request(struct nfs_page *req);
extern  int nfs_set_page_writeback_locked(struct nfs_page *req);
extern  void nfs_clear_page_writeback(struct nfs_page *req);


/*
 * Lock the page of an asynchronous request without incrementing the wb_count
 */
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
 */
static inline int
nfs_lock_request(struct nfs_page *req)
{
	if (test_and_set_bit(PG_BUSY, &req->wb_flags))
		return 0;
	atomic_inc(&req->wb_count);
	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);
	req->wb_list_head = 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);
	req->wb_list_head = NULL;
}

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
	19	#include <asm/atomic.h>
	20
c6a556b8 TM	21	/*
	22	* Valid flags for the radix tree
	23	*/
3da28eb1	24	#define NFS_PAGE_TAG_DIRTY 0
c6a556b8 TM	25	#define NFS_PAGE_TAG_WRITEBACK 1
c6a556b8 TM	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 LT	36	struct nfs_page {
	37	struct list_head wb_list, /* Defines state of page: */
	38	wb_list_head; / read/write/commit */
	39	struct page wb_page; / page to read in/write out */
	40	struct nfs_open_context wb_context; / File state context info */
	41	atomic_t wb_complete; /* i/os we're waiting for */
	42	unsigned long wb_index; /* Offset >> PAGE_CACHE_SHIFT */
	43	unsigned int wb_offset, /* Offset & ~PAGE_CACHE_MASK */
	44	wb_pgbase, /* Start of page data */
	45	wb_bytes; /* Length of request */
	46	atomic_t wb_count; /* reference count */
	47	unsigned long wb_flags;
	48	struct nfs_writeverf wb_verf; /* Commit cookie */
	49	};
	50
	51	#define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags))
1da177e4 LT	52
	53	extern struct nfs_page nfs_create_request(struct nfs_open_context ctx,
	54	struct inode *inode,
	55	struct page *page,
	56	unsigned int offset,
	57	unsigned int count);
	58	extern void nfs_clear_request(struct nfs_page *req);
	59	extern void nfs_release_request(struct nfs_page *req);
	60
	61
3f442547 TM	62	extern long nfs_scan_dirty(struct address_space *mapping,
	63	struct writeback_control *wbc,
	64	struct list_head *dst);
d2ccddf0 TM	65	extern int nfs_scan_list(struct nfs_inode nfsi, struct list_head head, struct list_head *dst,
d2ccddf0 TM	66	unsigned long idx_start, unsigned int npages);
1da177e4 LT	67	extern int nfs_coalesce_requests(struct list_head , struct list_head ,
	68	unsigned int);
	69	extern int nfs_wait_on_request(struct nfs_page *);
	70	extern void nfs_unlock_request(struct nfs_page *req);
c6a556b8 TM	71	extern int nfs_set_page_writeback_locked(struct nfs_page *req);
	72	extern void nfs_clear_page_writeback(struct nfs_page *req);
	73
1da177e4 LT	74
	75	/*
	76	* Lock the page of an asynchronous request without incrementing the wb_count
	77	*/
	78	static inline int
	79	nfs_lock_request_dontget(struct nfs_page *req)
	80	{
a911fd9a	81	return !test_and_set_bit(PG_BUSY, &req->wb_flags);
1da177e4 LT	82	}
	83
	84	/*
	85	* Lock the page of an asynchronous request
	86	*/
	87	static inline int
	88	nfs_lock_request(struct nfs_page *req)
	89	{
	90	if (test_and_set_bit(PG_BUSY, &req->wb_flags))
	91	return 0;
	92	atomic_inc(&req->wb_count);
	93	return 1;
	94	}
	95
3da28eb1 TM	96	/**
	97	* nfs_list_add_request - Insert a request into a list
	98	* @req: request
	99	* @head: head of list into which to insert the request.
	100	*/
	101	static inline void
	102	nfs_list_add_request(struct nfs_page req, struct list_head head)
	103	{
	104	list_add_tail(&req->wb_list, head);
	105	req->wb_list_head = head;
	106	}
	107
1da177e4 LT	108
	109	/**
	110	* nfs_list_remove_request - Remove a request from its wb_list
	111	* @req: request
	112	*/
	113	static inline void
	114	nfs_list_remove_request(struct nfs_page *req)
	115	{
	116	if (list_empty(&req->wb_list))
	117	return;
1da177e4 LT	118	list_del_init(&req->wb_list);
	119	req->wb_list_head = NULL;
	120	}
	121
1da177e4 LT	122	static inline struct nfs_page *
	123	nfs_list_entry(struct list_head *head)
	124	{
	125	return list_entry(head, struct nfs_page, wb_list);
	126	}
	127
	128	static inline
	129	loff_t req_offset(struct nfs_page *req)
	130	{
	131	return (((loff_t)req->wb_index) << PAGE_CACHE_SHIFT) + req->wb_offset;
	132	}
	133
	134	#endif /* _LINUX_NFS_PAGE_H */